I had this idea quite a while ago, and i still like it: So the idea is like a flieing insect(evil butterfly).
Passive(Pestermites): Vivisect does not use mana. Instead he gets a pestermite every 5/4/3 seconds.They deal 3/4/5 damage to surrounding units(bout like Sunfire Cape) and he gets 1+0.1/lvl Armor and magic resistance per pestermite. .Max. 5/6/7 Pestermites.
Q-ability:(Kamikaze!)(Costs 1 Pestermite)(5, 4.5, 4....CD) Shoots 1 Pestermite (like a skillshot).It explodes and deals 50/80/110.... magic damage and poisons for 5/10/15/20/25 damage per second for 4 secondsin a small AoE(175).(AP ratios:0.6 and 0.3)
W-Ability:(Trail of Gusts)(Costs 3 Pestermites)(20/18/16/14/12 CD) Leaves a trail of little Pests behind him for 3/4/5...secs dealing 20/32/44 magic damage per second and slowing targets for 20/30/40...%(Ap-scaling-0.4)
E-Ability:(Subcomb)(passive) Gets 5/6/7/8/9 life regen per 5 seconds per surrounding dead units.(they stay for 6 seconds) (Active:)(Costs 2 Pestermites)(10,9, 8.5, 8, 7.5... CD)Infects an enemy, dealing 80,120, 160, 200, 240, damage and if the target dies in the next 4 seconds he gets 1/1/2/2/3 Pestermites back.(AP-ratio:0.8 only the damage)
R-Ability(Ultimate)(Swarming Passage)(Costs:as many as you have)(120/100/80 CD)Surrounds(and shields) himself with a big egg that slows all enemies surrounding it(70%)(HP 200/250/300+30/40/50xPests). If it gets destroyed or after 4 seconds it explodes, dealing 100/170/240+30/40/50xPests)and spawns 1xPestermite Spiderlings, having 150/200/250+10/lvl) and ad(45/70/115) (Ap-ratio-1.2on the damage)He can't get interrupted until the shield is down.
Health:394+ 88/lvl Ad:53+ 3.5/lvl Range:470(thought about melee before though)
As:0.6+1.55/lvl Armor:15+3.5/lvl MagicRes:30 Movement:300
Quotes:-Pick:Very well..../Be part of the swar'm!
-Move:I am the Swarm!/Come, children!/We are not amused!
-On Death:We cannot Die!
-Taunt:Maggots shall eat you!
-Joke:The real may break the butterfly, but the Butterfly will break you!
Thx, that's all, constructive feedback is welcome.