Hi, i'm DeleDulux i'm a player of League of Legend just like you and i will help you with your experience in this game, let'so go.
Sorry if there are grammatical errors in English but I am Italian so I am not a native speaker of English

PROS:

- Really strong and fast in cleaning jungle
- Your Early Game is really strong beside every enemy jungler
- Solid tank with a lot of damage with the possibility trap an enemy
- Good in Late Game
- Good to use when you have no tank

CONS:

- Few items in your build to choose
- Difficults ganks in others lains
- Same runes every game
- Others junglers can scale better than you
- Not really good when you already have 2 tanks on your team

Let's talk about your SYNERGIES.
Your best is to have someone that stuns/slows/silences the enemy to get your E and get an easy kill, another thing that must be knowed is that have more than 2 tanks on your team can mean your end is near the can easly build 3 anti-tanks and you will loose for sure the mid/late game.

Here are some tips on what you should like to have in your lains:

TOPLAINERS: Like every toplainer is good because all of them stuns/slows/silences but you realy like to have an Assassin top lainer or someone that isn't a tank

MIDLAINERS: You like everyone here because if he's a Magician or an Assassin at least you are sure to not getting a tank mid lainer

BOTLAINERS: Your ADC is your best friend because of his long range damage so everyone will be good.
You support can be tank when your top are choosing to not pick a tank champion, everything that can grab or root an enemy champion is your best synergies

COUNTERS: All counters in jungle are written in the threats

My rune is ONE as you've seen you can change only 2 things now i'm going to teach you when you should change your rune

CHANGE ALACRITY with TENACITY: Is a thing you can do when they have a lot of enemys (expecially the enemy jungler) with CC, if the enemys haven't got or have a low percent of Cc DON'T CHANGE ALACRITY because is really good for you in fights, you need that attack speed.

CHANGE EYEBALL COLLECTION with TASTE OF BLOOD: I never change this because you need more damage than lifesteal, you need damage because with Riftmaker you already have a good amount of lifesteal, so DON'T CHANGE EYEBALL is really stronger than taste of blood

Start: You're start will be for sure with EMBERKNIFE + REFILLABLE POTION because is the best on Mordekaiser(or HAILBLADE variant).

1st Item: Riftmaker is your ONE and ONLY choice as first item, i really like to build leeching leer and boots because Mordekaiser against other junglers hasn't got a lot of movement and Leeching has a good global lifesteal.

After first item: So you have builded your Riftmaker now you must choose from 2 path:

- Build Boots
Building Boots is the best for more movent speed and will help a little in ganks.

- Build Nashor Teeth
Building Nashor is the best for fighting you gain more attack speed and helps a lot in fighting enemy .

So my advice for your first time is to BUILD RECURVE BOW and FINISH YOUR BOOTS.

This is what I ALWAYS buy after Riftmaker obviusly this depend on what you team needs if you are loosing in lains you should go for BOOTS, if your lains are in a tie(or 1 kill difference) you can get 2 DAGGERS and build BOOTS, if your lains are winning you should go for RECURVE BOW and BOOTS

(THIS IS MY OPINION IN GENERAL BUT EVERY GAME CAN BE DIFFERNT SO THIS IS NOT MAKING SURE THAT YOU WILL WIN EVERY GAME)

Ok here we are, you have 3 items and you now must go for the 4th so if you read notes you will see that every item has is note but now i give you more details for every item:

- ZHOYNA: is an OCCASIONAL ITEM, good VS enemies ultimate like KAYN,FIDDLE,AMUMU,JARVIS,YI,ZAC,NUNU.
I don't build it even when there are those champion vs me but sometimes this item can save you so if you see that Zhoyna can help tou in fights or teamfights build it is not a waste of gold but i usually don't build this item as 4th but as 5th or last.

- RYLAI: is REALLY GOOD item for Mordekaiser i build it like every game is really strong with your abilitys.
This item is FIRE with Mordekaiser trust me when you gank is a really pain especialy when you grab someone with your E is like a 100% kill, i build this item as 4th like always BUT be sure to deal a good amount of damage because if you don't is a waste of gold.

- MORELLON: is OCCASIONAL, good againts enemy with high lifesteal so if you see 2/3 picks with lifesteal just build this.
This is like Zhoyna but i often build it because you actually find always someone with a lot of life steal but DON'T build this item vs an only one enemy with life steal but with 2/3 enemies can be very good, i buld this item as 4th ONLY if there are a lot of lifestealer, if the have no lifestealer DON'T build this item.

- DEMONIC: it helps a lot in fights giving you damage and health so is always a great choice.
This item is good and is one of the best item on Mordekaiser i take this item like everytime in my build (as 5th or last item) trust me when i say that this item will make you gaining more power and MORE health i really TANK a lot with this item and after gaining some power as 4th item is like the best way to surviving.

- COSMIC: item works as 4th item very well gaining more damage and moviment will help you in ganks and contesting objective.
THIS ITEM IS MY FAVORITE on Mordekaiser is like the best 4th item on him this item give you more speed and more damage and is like going in a gank doing Q and dealing half of the life of the enemy champion, i REALLY think you should always build this item on your build (preferably as 4th)

PASSIVE: Is just activating when auto attacking or using abilities on every monster of the jungle or a champion so is so good to do Raptors,Wolfs and Rocks.

Q: This ability is the most damage dealer of Mordekaiser so remeber to max it and spam everytime in a fight and in jungle to go faster in camps.

W: This ability is your shield and heal, you should use this ability when your bar is full to get more shield in fights and use it in jungle when you have low health or you wanna heal up.

E: This ability is the most usefull of Mordekaiser so DON'T use it when you are not sure to get the enemy, when you find a champion with a lot of mobility just wait for the right moment because this ability CAN'T be wasted.

R: Basically the best ability for ganking, when you are ganking(WITH OR WITHOUT YOU LAINER)this ability will help you a lot but remeber to not abuse of it, your main quest is to help and not steal kills, OBVIUSLY you want to use your R when your teammate are dying in lain that will safe him and you will get a free kill.

As jungler your role is to do your camp and help in lains so your early game is farming camps and gank, let's start with farming camps and your first gank.

RED START: Starting with your Red is a good choice for dealing burning damage on minions, and my Red rotation is RED>ROCKS>RAPTORS-WOLFS>BLUE>GROMP after that i go to contest the scuttle crab and gank TOP/MID, if the enemy jungler gets the scuttle BEFORE you come GANK MID and go to the other scuttle and do it or you'll loose the first step of jungle

BLUE START: Starting with your Blue is a good choice to have always the full mana, and my Blue rotation is BLUE>GROMP>WOLFS-RAPTORS>RED>ROCKS after that i go to contest the scuttle crab and gank BOT/MID, if the enemy jungler gets the scuttle BEFORE you come GANK MID and go to the other scuttle and do it or you'll loose the first step of jungle

After your first gank you can chioose one of this way:

-You recall: I usually never do this until i have 1300/1600 gold, but if you health is very low after the gank you can recall and buy Boots and Ruby Crystal.

-You go invade: This is risky but even getting a single camp of your enemy can help you a lot to fight the other jungler in early, so do this when you are REALLY SURE to get a camp without fight enemy jungler.

-You gank again: This is pretty simple, you have already ganked a lain but the other lain is been under farm or is in a difficult farm, then your gank will really help him and you may get a kill.

I always do 2 ganks for pressure the other enemy lainer but if my lains are in priority i always go in the enemy jungle because or early game is really strong against every jungler.

For jungle objective you don't really need help from other lains.

The DRAKE is pretty easy you can do it if you are full health(AND IF YOUR LAINS AREN'T BEGIN PUSHED) and can be done at the moment that he spawns just remember that having a little help for the first time with Mordekaiser in jungle is always good.

The HERALD is easy to do even alone with low health just make sure that the enemy jungler isn't near him.

JUNGLE TIPS:

- Try to make Mordekaiser PASSIVE always active while doing half of your camps(RED SIDE/BLUE SIDE, with a bit of pratice you can easly do this (if you use you E through the walls is more easy to maintein)

- Ganks can be difficult to do when you are new as Mordekaiser, my tip is to be sure to grab the enemy with your E and than do your Q and then just AA if you do this you are sure to get a kill or an assist.

Your matchups at the moments will probably be an Assassin or MORGANA so don't be scared Assassins are really weak against you.

the most banned champion when i use Mordekaiser is Lee Sin because he's really strong at the moment and is really easy to use.

Another pick that is the most stronger vs you in early is Shaco so he can be a good ban.

Master Yi is good against you in Mid Game if he's feed so you can ban him if you want.

Morgana is strong so if you're support don't ban her is a really good ban to make because of his range and damage.

Last are those champions that can tank like you or with ranged.

Tanks will be a match when who deal more damage and tanks more win.

Ranged will be a match of trying to catch them, muy advice is to not fight them if you are new with Mordekaiser or fight them when they are in your range.

Ok we arrived to the Mid Game and now you become a little bit weaker if you haven't farm or get kills/assists.

You can start TeamFights with Mordekaiser R with grabbing the enemy ADC, the enemy TOPLAINER or the enemy JUNGLER (only if he's tanky or ranged).
My advice is to get the most fed and kill him with your R, OBVIOUSLY only if you are sure to kill him, i presonally try to get the ADC because of his high damage but the low health, so you are sure to get the kill him and doing it in a very short time, after that your team could've just already won the TeamFight, if they don't help them to get the last champions of the enemy team and win the fight.

Another thing you wanna do for making sure to get you more stronger is to not focus on one target because your abilities has a lot hitbox so don't aim for just one champion, this because you want also to keep you PASSIVE active at the start of the TeamFight for dealing some damage with it.

One great thing you must have is the first turret of every lain down and the mid 2nd turret down, so make sure to place the at least one HERALD in mid.

Remeber to do the jungle objective afeter EVERY TeamFight, BARON has priority then DRAKES and if there aren't any of these just push one lain, do not waste the won fight.

If you haven't already finish the game you now should go (if you haven't already got them)for the FOUR DRAKES, DRAKES will help you a lot in TeamFights so do them, if the enemy squad had already got the FOUR DRAKES you shouldn't really let them engage your team, if you find someone of the enemy team alone and with your team must chase him and get the kill, this will really be more easy for you and your team to fight them, if they don't fight you try to close the game by pushing all in one lain.

In this part of the game you really want to have all the enemy INHIBITORS destroyed but an alternative can be 2 INHIBITORS destroyed(MID HAS PRIORITY) or MID INHIBITOR destroyed

Thanks for reading my MORDEKAISER JUNGLE BUILD more build will arrive, now you can go and CRUSH everyone with this build.

I will really like to know your opinion so don't hesitate to letting me know if my build has helped you or you think something can be better in the DISCUSSION section, thanks and HAVE FUN