Here's the skillset i made for Kit. Just thought it up really quick (less than an hour) and it could use a lot of balancing I'm sure, but I hope you like it! (I'll add the names, costs, cooldowns, and ranges later, don't have time for that right now)
Passive:
When out of combat, Kit can mark the area he is standing with his symbol at by clicking a button above the ability icons (similar to Kindred). In a 2500 range around this mark, Kindred gains various buffs listed below. This marked area lasts for 3 minutes but can be destroyed by an enemy by attacking it 5 times (like a pink ward). When destroyed by an enemy, this grants 30 gold. Once an an enemy gains vision of this, they can see it until it disappears. (Cooldown: 2 minutes after symbol is destroyed or disappears)
Buffs while in this area:
+10% Movement Speed
Vision of 500 units around the symbol
Basic attacks deal an additional 10 (+3 per level True Damage)
Q:
Kit’s next basic attack splatters ink in an area around the target, dealing an additional 50/80/110/140/170 (+35% AD) Physical Damage to the first enemy hit by the basic attack and half that damage to all enemies in an area around them. Only applies an Ink Mark to the enemy hit with the basic attack.
W:
Passive: Kit gains 10/15/20/25/30% Movement Speed while within 1000 range of an Ink Marked enemy.
Active: Kit paints a ring around himself, creating a zone of healing for allies. This ring lasts for 5 seconds and heals allies within for 12/24/36/48/60 (+8% AP) per second. 5% of the damage dealt to enemies within the ring is stored. When the ring disappears, that amount of health is restored to allies who are still within the ring.
E:
Kit dashes in a skillshot that does nothing, however after a 1 second delay, this can be cast again within 5 seconds as a targeted ability that will deal 50/90/130/170/210 (+10% of the target’s current health) Physical Damage and stuns the selected enemy for 0.75 seconds.
R:
Passive: Whenever an ability hits an enemy, they’re Ink Marked for 3 seconds. These 3 seconds are reset whenever an ally attacks them while marked. After 3 basic attacks by Kit or 5 basic attacks by allies, an Ink Marked enemy’s vision is reduced for 1 second (in the same way as Nocturne’s ultimate or Graves’s Smokescreen) and the enemy is slowed by 20/30/40% for 1 second.
Active: Kit channels for 2 seconds, planning the path he’s about to take. When those 2 seconds are over, or the R button is pressed again, Kit dashes along the path, dealing 150/250/350 (+40% Bonus AD) Magic Damage to all enemies hit (50% reduced for each successive hit if it hits an enemy more than once) and leaving a trail of ink that lasts for 3 seconds. Enemies that walk through the ink trail are Ink Marked as well. If this hits an Ink Marked enemy, their Ink Mark is detonated.
(Think Master Yi’s meditation as an animation except a symbol painted underneath him during the channel followed by Kit dashing at a very fast speed)