Kog vs Jinx identity
Back in season 5 I played a lot of Jinx and Kog maw. they can have similar feels but their end game dreams have important differences. I feel like an important and obvious destination between Kog and Jinx is what kind of team you want to play them against.
Old Kog (the one who's coming back) did some flat damage with his build, but he was primarily ℅ health based damage. Kog is inherently a tank buster.
Jinx both in mini or rocket form deals damage as flat as. .... Well, Jinx. She has to buy a botrk if she wants ℅ health and even then botrk scales poorly on her because of how well rockets scale on AD and crit. She can still melt tanks but not as quickly. That being said? Flat damage is wonderful against squishy targets! This gives her an edge over Kog against some teams!
Also, between her chompers and her passive, Jinx is a lot more forgiving with positioning errors than Kog is. Jinx is a great beginners late game hyper scaling immobile ADC.
Kog maw is not so great for beginners, but he's still a lot easier to use effectively than vayne.
Their identities will basically be this:
Jinx is for when the enemy team has a variety of health bar sizes. She takes on squishies very well. If her team protects her, her single target damage can go up massively with her mini gun. If not? She can retreat to the range of her rockets and play like lux while still contributing.
Kog'Maw is for when the enemy team has at least two really beefy champions. You have multiple large health bars to melt. The enemy team has a cho'gath top and a tank sejuani jungle. You need a team to protect you to do your job. No excuses. No safer option. Your reward for this is the ability to melt tanks in seconds flat. You really need to be aware of your windows of opportunity because once you pop w you are committed to go in or to give up your major damage and safety for that team fight. Your team may be forced to retreat or at least wait until it's back off cooldown and that can mean giving up an objective.