Hi Mobafire! My summoner name is WujuDesu, which is based on my real Korean name Wooju(meaning space). You are probably guessing one of my favorite champions is from Wuju. If so, your absolutely right! Master Yi is one of my dearest, most sentimental champions if not the favorite. Aside from Yi, I main Riven and Katarina.

I started league during the summer of season 4. Because I had previous exposure to MOBA, I was slightly better than average players. After my first provisionals, I was placed in silver 2, and I stayed in silver for a longgggg time as a result of both poor mechanical skills and map-reading/shot-calling knowledge. Having been a silver guy, I very well remember the irreversible habits of silver players: desiring kills merely for in-game KDA, not knowing when to back off while sieging, dying repeatedly to ganks because you don't ward/unaware of where enemy jungler/mid is, "suiciding" for a potential kill, etc. If you can personally relate to these issues, don't worry. You're not alone; I was there too, and the good news is you can fix these habits by thinking rationally and playing smart. By constantly evaluating a decision you or your teammates are about to make, you can lower the chances of making a mistake. Combining this thought process with slightly better mechanics is what got me to Diamond in less than a year.

Accounts:
https://na.op.gg/summoner/userName=wujudesu
https://na.op.gg/summoner/userName=riven+in+eroge

Throughout my champion guides I'll repeatedly provide general gaming tips, and I guarantee that reading and applying my guides will not only make you better at specific champions, but also a better player overall. Thanks guys and let's kick some ***!

Katarina can either be super fun or very frustrating to play depending on the flow of the game. This is because she is generally weak, but has a massive snowball potential when she's ahead. The main problem with Katarina is that she does not provide reliable damage in team fights since her damage output is determined by how many skill rotations she gets due to resets. In the current meta, the role of the mid-laners seems to be providing consistent damage (dps) and much cc/zoning control (Hence we see picks like Azir, Viktor, TF be prevalent in competitive settings). Unfortunately, Katarina provides none of that, and assuming she's about even with her opposing mid-laner, her damage output of a single skill rotation cannot match against its counterpart. Her weakness is further accentuated by her poor laning phase, as she often gets bullied by other laners who probably have better harass and wave clear. Sometimes in low elo, people do not know how to properly trade in laning phase, so Katarina might out-poke her opponent with her q, and eventually get a kill. Sadly, this is often not the case in higher elo, and Katarinas generally can't get a kill in lane without jungle assistance. Well I did bring up many negative points about Kat, but don't be discouraged to play her because of these weaknesses because unlike the pro-scenes, solo-q can be quite uncoordinated and unpredictable. And this is how Katarina can shine.

Pros
- Massive snowballing potential
- High AOE damage output with resets
- Decent utility
- Slippery; hard to lock-down because of her E

Cons
- Susceptible to CC
- Useless against Peel/Disengage Comp
- Poor Laning Phase
- Unreliable Damage Output in Teamfight
- Ultimate easily countered by summoner spells i.e. flash/heal/exhaust

For item choices, please refer to the appropriate page.
There are two pages: one for vs ap and another for vs ad.
For explanations of item choices please read the notes below.

There is no definite item purchase order as it is always situational.
Think about the ap:ad dmg ratio of you and the enemy team.
Also account for how ahead/behind you are in buying items.

1) Q + E + W + (R)
This is pretty general, and ideally should be used every time.
Spamming is important to fit in W before R but be careful not to accidentally cast something else first because that can easily mess up your combo. For example, I still make the mistake of ulting before I jump into the crowd, which deals minimal damage to front-liners and guarantees you 0 reset.

2) E + Q + W + (R)
Sometimes it's hard to catch up to your enemies because of their escape abilities or kiting ccs. In that case, it might be better to E to your target first. Because Q has a spell casting time unlike e, your enemy might out-run you after you land a Q.

3) Q + E + AA + W + Move Forward + AA + Repeat until you can finish with R
When you know that you can't 100-0 someone up in a 1v1 situation, know you can out dual him, and can afford to chase him, this is what I do to chase. Katarina has one of the higher base movement speeds, so average speed, inescapable champion shouldn't be able to out run her. If you see a lone support that you can't one-shot, but can kill overtime, use this method.

4) Ward/Minion/Champion/ETC Hop + Q
If you see someone that is one hit away from dying, just hop somewhere or you put a ward out to hop and q to get the kill. This is one of the places where Smart-Casting (Quick-Cast) can give you an edge.

5) Hop somewhere + Q + W + (R)
This is somewhat similar to (4) but different in a sense that you are not simply an AA or Q away from killing but your enemy has a little more health. When you see someone, for instance, an AD carry with 1/3 health and know you can't reach her, hop to an object (probably a nearby minion or insta-ward-hop) and use this combo. Because of W's movement speed buff, it's best to move forward a little after W to get the most out of your ult.

APPLYING SUMMONER SPELLS
During laning phase, poke your enemy mid-laner to about 1/4 health using Q+E+W combo or just Q if you can't out-trade with the former. Now when you have Q.E.W again and hopefully minions are under enemy tower, keep a considerable distance first and Flash + Q + E + W + Ignite to tower dive and e out (insta-ward-hop if necessary). The key here is to be unpredictable because once your enemy notices and backs out, you likely lost your chance to kill him. In low ELO, you are guaranteed to get first blood 50% of the time like this. In higher ELO, people might already know this, so don't expect too much but it's still worth trying. Be wary of summnoners like barrier and heal!

The combo I mentioned can also be used to instantly one-shot carries. It is not recommended to initiate this way in team fights as your best outcome without Zhonyas is going 1 for 1.

Relate back to the moments when you are playing a solo-lane (sometimes even jg) and you die for the third time. By now your teammates are probably flaming at you. Your excuse might be...? I got ganked and lost lane. What can I do... Their reply? Ward and play safe idiot!

For most, nothing is more frustrating and infuriating than losing lane because of an enemy jungler's assistance. Sometimes you can get massively behind in lane only by losing farm and experience due to jungle pressure, but in most cases people get behind by dying to ganks. Dying not only gives your opponent kill/assist gold, but also gives him direct xp advantage and allows him to further deny you farm. If you die under your tower without tp, you would probably lose 2-3 waves, meaning your opponent would be 2 levels higher than you and about 1000 gold up. If you get yourself in that situation you have little chance of coming back in lane and you'd be probably be a liability to your team. Having said that, it's crucial for one to not die in lane, even with the enemy ganks. And one way of preventing ganks is warding.

HOW Often should I BUY Wards?
The cardinal rule in buying wards, in my opinion, is to invest in at least 1 Stealth Ward and 1 Vision Ward every back if you can after purchasing an item. Of course, since you can't place more than 1 Pink ward, you don't need to buy one if yours is not detected. Thanks to the trinket upgrades, you can now mitigate ward expenses after lvl 9. I suggest upgrading to greater stealth totem especially when behind to keep the nearby jungle and river warded.

For Katarina specifically, it's always good to have one stealth ward available in your inventory so you can always have the option to ward hop. This becomes less of an issue after you upgrade your trinket to greater stealth totem.

PLACEMENTS
(I'd like to add some pictures for this section, but I'm too lazy to do so -_-, maybe I will in the future). So you bought the wards; good, now you need to know where to place 'em. You can place green wards pretty much anywher in the map.

The first priority in warding should be warding ganking paths. So in mid-lane, for example, you should ward somewhere around the right or the left bush first. Sometimes it's better to ward paths the enemy jungler takes to gank you so you can react to their movement faster.

Your next priority can be warding your enemy's jg to know where the jger is/likely be. The benefits of this follows:
1. Useful for your own positioning and aggression.
2. Informs other lanes how much aggression is appropriate.
3. Informs your jungler which lane is not vulnerable to counter ganks.
4. May give opportunity to counter jg or kill their jger while he farms jg camps with low health.

You should also ward both rivers to quickly detect any roamings from their mid, top, or even support. This also allows you to know whether they are doing dragons/barons.

Pinks should be placed generally on bushes, unless its purpose is solely for denying vision while taking objectives or reducing invisible flank threat (i.e. rengar, shaco).
The two most common places for pink are the river middle bushes near baron/dragon. Though this place is checked often, putting a pink there provides enormous map control and prevent cross-map ganks. It also assures you that side of the river is not warded, facilitating covert activities - sneak drag/baron, roaming...

It's not a bad idea to put a pink in bushes that are rarely walked upon. For example, instead of the middle bushes in river, the ones above them. This grants you less map control but guarantees better chances for a longer survival. After all 100 gold ward can stay untouched all game!

When you are trying to defend your base, you can put a pink on your side of the wall to clear enemy wards, which make them easy to harass or get a pick.

Think Katarina as a part-time jungler. Post 6, your job is to help other lanes succeed (and/or help yourself) by killing other enemy laners or at least providing some pressure. You can roam Pre 6, but unless the enemy(s) are super low for you to combo kill, it's rarely effective. Honestly, Katarina is a bad laner, and probably one of the worst. That's why mid, mid-late game is where she shines. And to prepare for her prime time, you should roam.

I mainly roam bot lane as it is usually the most volatile lane. But roaming top is also an option when you know you can secure a kill. If you do get a kill or two or at least made enemies back, you may get an opportunity to finish off a tower early, which is great. The whole point of picking Katarina is to snowball early, and to do that, you need to help other lanes win by roaming.

Because of the nature of Katarina, tower diving is mostly okay, but be careful of enemy summoner spells. Summoners like heal, flash, and exhaust are usually the spells that fu** you up in general and especially in tower diving. Make sure you always ignite an adc/support unless you know FOR SURE that their heal is down. If you ignite before they heal, heal only increases their hp by 50% which substantially increases your chance of securing a kill and a reset to get out.

If you have snowballed early and ensured your allies' victory in their lanes, you don't even need to know much about team fighting to win. You can pretty much kill anyone you want (with or without your teammates) by casting your combos and bursting them quickly before they get a chance to react (usually works with flash). If your teammates are dominating and can chunk your enemies' hp down massively for you to clean up, or you just got a pick making the situation 5 v 4, securing kills and objectives should be easy. This scenario is very common as a fed Katarina, and unless you or your teammates throw, it should be an automatic win.

The team fights that I am talking about here refer to ones that happen when both teams are in equal footing or your team is losing. If this is the case, Katarina is heavily dependent on your team to do enough damage and disable the enemies with their cc so you can safely cast your ultimate. Sadly, I've discovered that when Katarina has to rely on team-fights to secure kills and objectives, she already has more than 65% chance of losing the game. What do I mean by this? I am saying that as the game gets elongated and prolonged, enemies grow more resistant to Katarina's bursts. When tanks and bruisers alike get tanky and have much mr, Katarina alone cannot finish enemies and get reset, making her virtually useless. By super late-game, an adc should have a blood thirster and perhaps a banshee that makes it so hard for you to one-shot her, and the midlaner probably has zhonyas. A Katarina that dies without a reset is a REALLY depressing Katarina, and if that is the case, you have to rely on your adc or others to carry you. *Note that with her passive Voracity nerf, (now reset occuring only within 3 seconds of Kat dealing damage) reset is even harder in late-game teamfights.

If I am in this situation, what can I do to help out my team the most?
Before I go into explaining her role in team-fights, let me just tell you that your best bet is to turn the situation upside down as soon as you can. Try to make plays and acquire triple, quadra, or Penta kills (i.e. force Baron, Dragon, Tower Dives by roaming). Easier said than done, but do look for reasonably risky opportunities that can largely put you/your team considerably ahead even though failures can worsen the situation. The longer the game gets, the worse it is for you and your team.

With the removal of DFG, your role in late game team fight has changed a bit. Before it was mostly to assassinate the enemy adc (or apc) to get the reset (and try to clean up/ not die). Now you can hardly do that since Adcs would get peel from their teammates and/or have bloodthirster and mr to prevent one-combo-death. Sadly, no matter how many items you have, you just don't do that much burst damage without DFG. Adcs, if they are not dumb, stay in the back line, so if you engage on them, your teammates can do little to help or save you, which would make the situation very disadvantageous for your team as it would be a 4 v 5.
(It's mostly the same with trying to assassinate APCs because they'd have zhonyas to mitiage your ultimate damage and get peel).

So now here is what I think Katarina should do now. You should literally go in and ult the most amount of people (preferably the squishy side) after most of enemy ccs are used or if they are disabled by your teammates' ccs. If you see yourself not getting a reset before you die, activate Zhonyas at the appropriate time and back off until you get a reset to execute another combo.

Mechanics if you do get a Reset
A wise man named Scarra (yes Scarra) said you should E + W immediately after you get a reset since Q has a casting time. So just spam E and W first after you get a reset, and use Q if it's necessary to finish someone up. That way you'd be least likely to get cced in the process and lose an opportunity get a lot of rotations off the enemies run away. Also, fight the temptation to zhonyas before doing enough damage to get potential resets, but do zhonyas when an enemies are about to land a heavy cc on you. This will make it a lot harder for your enemies to lock you down and deal damage to you allowing you to be safe. For instance, you can probably dodge Cassiopia's Ult, Annie stun (Q or R), or Nautilaus' Ultimate, etc if you activate zhonyas at an appropriate time (look out for the casting animations).

Another thing worth noting after a reset is examining how much health other enemies have. If they are all low enough to kill, then get more resets by E + W (and if necessary q) If they aren't but you have a teammates backing you up, either Q + E + W (or Q + W) and back-off or wait until your teammates gets someone low enough for you to kill with a combo. If you are not backed by your team and find yourself unable to get additional resets in anyway after one reset, Shunpo backwards quickly to disengage. The key here is not get cced in the process (which would make you get focused and result in death or at least massive hp loss.

Thanks for reading my guide to the bitter end.
I'll keep updating it as I see fit.
If you have any questions or suggestions, feel free to comment.

Best Wishes,
WujuDesu