Hi, welcome to my On-hit bruiser fizz guide! This is my first guide so please leave feedback.I plan on adding a matchup section and my scores soon. Also I plan on adding more images and formatting it better somewhere in the future, but Im not too good with BBCode yet, so please be patient :)

Even though it sounds troll, Fizz's kit allows him to be a very powerful bruiser, and he is able to outduel many top laners and deal a significant amount of damage to tanks. His W makes trading autos easier and reduces healing from those pesky healers (Mundo, Volibear, Sion, etc.). He can also escape ganks easily and chase enemies, and the slow and AoE knockup from his ultimate are a great addition to teamfights. As a bruiser, you get more DPS and tankiness than AP fizz, at the cost of your burst.

Pros: -Great duelist -Great base damage and utility on ultimate -His mix of physical and magical damage makes it hard to itemize against -Ungankeable if played right -Healing reduction -Amazing sustained damage -Great chasing potential

Cons: -Low burst -Squishy early game -Needs farm -Attack speed reliant, making frozen heart and randuin lower his dps -You'll be flamed for going bruiser fizz dasdasd dasdasd dasdasd dasddas

Quintessences: Hybrid pen quints are the best quints for fizz, although expensive. Magic pen quints are a good alternative. Other viable choices are Attack speed, movement speed, and HP quints.
Marks: I usually go 9 hybrid pen marks, you can replace them for magic pen, but you will lose damage.
Seals: Flat HP seals are good since you are squishy early game. You can also take HP per level, since they are better lvl 6 onwards than its flat counterpart. Armor seals were nerfed, but still a good option.
Glyphs: MR per level are good for lategame, since most mid laners deal a good amount of damage at that point in the game. Take flat MR if going against an AP top laner.

Flash is the most useful spell in the game, so take it. You can take Ghost instead, but I think flash is better. Your second spell slot is more versatile, you can take Ignite for extra kill potential, but don't take it only for the healing reduction effect since you already have it in your W. Exhaust is a good spell too, great for dueling champs like Fiora, yi and tryndamere. Teleport is great for ganking other lanes and getting to teamfights faster. Other spells aren't that good on Fizz, so don't take them.

Nimble Fighter Passive: Your passive makes you ignore collision and suffer less damage from autoattacks. This, combined with a Doran blade, makes trading autos much easier for you early game. It is also great when going against ranged champions since it reduces their harass.

Urchin Strike Q: This skill works as a gap closer and disengage, and gives you more mobility than most top laners. It also applies on-hit effects, which is the core of this build. Max this third.

Seastone Trident W: This is your core skill, it is the reason why bruiser on-hit fizz is a viable choice. Its passive deals a percent of the oponent missing health during 3 seconds, combine this with ruined king and you will be dealing max health damage. Its active makes your autos apply healing reduction and extra magic damage, and has a low mana cost. Max this second.

Playful / Trickster E: This skill lets you chase and escape ganks. Also in combination with your Q it gives you a lot of mobility and makes you able to perform amazing jukes. However, you don't need this skill as much as AP fizz does, so only take a point early game and max it last.

Chum the Waters R: This is your ultimate, it has a good base damage and great utility, and is on a short cooldown. Always max this first.

Starting items: Most games you'll want to start Doran's Shield since it gives you a bit of sustain and its passive sinergizes with yours. Take Doran's Ring if you want more poke and mana sustain. Take Boots and pots or Crystalline Flask if you need sustain.

Early core: Early game, you'll want Boots and Bilgewater Cutlass. Throw in a giant's belt if you are having trouble in lane or need extra tankyness.

Boot upgrades: You can upgrade your boots whenever you want, you'll want Mercury's Treads since they offer the rare stat of tenacity and also a bit of MR. You can also take Ninja Tabi if enemy team doesn't have too much crowd control.
Core items: Fizz only has two core items, the first being Blade of the Ruined King and the second being Trinity Force. Ruined king is the perfect item for bruiser fizz, it gives you attack speed, and a bit of attack damage and lifesteal. Its passive sinergizes very well with your W, and its active makes you even a stronger chaser. DON'T take both ruined king and triforce one after the other, finish ruined king first, buy a defensive item and then upgrade sheen.

After core: Once you have your core, you'll want tankyness by finishing your build with one of the next items, remember that you are NOT naturally tanky, so items that give both resistances and HP are prefered. Sunfire Aegis has good stats, its cheap and gives you an aura that helps you dueling and splitpushing. Randuin's Omen, even after the nerf it is a great item, with amazing stats and an AoE slow. Banshee's Veil and Spirit Visage are good options for magic resist, take one of them unless the enemy team is full ad. Frozen Heart is a great item on fizz if the enemy team is very heavy on ad, however don't take it as your first defensive item since it doesn't give any hp, and don't take it if you already have Iceborn Gauntlet. Warmog's Armor is a very good item, even if it doesn't give any resistances. Don't take it if the enemy team has HP shredders such as Kog'Maw. Frozen Mallet is also a good item, even though fizz is a great chaser already, the slow from your autoattacks makes it easier for your teammates to catch a fleeing enemy.

Other viable items: Wit's End is a good item and it can replace Ruined king, but only take this if the enemy team isn't stacking hp, since ruined king is generally better. You can replace triforce with Iceborn Gauntlet if you need more tankyness. I usually take triforce since triforce+BotRK gives you enough damage, but gauntlet is also a very good option. Take Ravenous Hydra if you think you are tanky enough but lack damage.

Early game:
As bruiser Fizz, you are going to need items to be effective, so you'll need to spend most of your time farming. You have great harass with your hit-and-run skills, so use that to your advantage, but don't lose creepscore in order to harrass, its never worth it. Once you have a few items, help ganking and with objectives.

Mid Game: Mid game is when teamfights and little skirmishes in dragon start. At this point, you should have 3 or 4 core items if you've been doing well and farming. Remember to keep farming, many people think you shouldn't farm after laning phase, but that's wrong. Keep farming lanes unless you are going for objectives or there is an important teamfight about to start.

Late game: Late game, you are at your full build, you deal a significant amount of damage and are able to tank a good amount of damage at the same time. Remember to splitpush if there aren't any teamfights or objectives to be done, and keep sight on Baron at all times. This is the time where a single mistake can cost you the game.

Teamfights: Teamfights with Bruiser fizz aren't that hard. You can use your ult to initiate, since the slow and knockup are great for your teammates to follow up. You are also a great diver, you can use your Q to go through the frontline and kill the squishies. You can use your E to back off in case something went wrong, so generally you shouldn't be afraid to dive. Remember that your W+BotRK gives your autoatacks a lot of damage even against tanks, also remember that your other spells won't do as much damage as you want, since you are not building any ap. Remember to initiate if you are sure your team will follow up, it is often a bad idea to let the enemy team initiate, since you are a bad peeler.

In conclusion, bruiser fizz is a strong option, altough there might be better toplaners he is still a viable choice and very fun to use. Thanks for reading my guide.