New champion idea, Dra'Nis the void dragon

So I have lots of ideas for champions, and i don't ever write my thoughts down, but i thought i'd start. Also alot of my ideas for this guy can be changed, just discuss what you think

Dra'Nis

The Void Dragon, or Prey Seeker (couldnt make up my mind)

Passive - At the start of the game Dra can mark a target as prey, every 2 kills/assist(more or less depending on how strong) on preyed target lets Dra upgrade an ability. Also, this would be up for discussion. I feel like he should be able to change his prey, so i was thinking that he can buy some item throughout the game, so he can change prey, that get exponentially more expensive as the game progresses, but i also thought that would defeat his purpose as campey jungler

Q - Plasma Breath - 4 second cooldown all ranks - 40/55/70/80/85 mana - 60/80/100/120/140 magic dmg .15AP Launches a Plasma ball onto the ground, marking his targets. If attacking marked targets gain 6% lifesteal on target. mark last 3 seconds

Evolved - Fireballs cooldown is decreased to 3 seconds and lifesteal bonus is increased to 8% (Think of a corki phosphorus bomb, but smaller radius and faster travel time.)

W - Void Flight - Cooldown 18/17/15/13/10 - 100 mana, or a high number at all ranks, i want this to be a mana killer - 70/90/120/140/170 physical dmg .30AD Flies at opponents, slowing where he lands by 10%

Evolved - passive - Every 5 seconds while out of combat gains movement speed, stacks 3 times. 25/50/100 movement speed (Was thinking of a 10 second cooldown once you get outa combat so its not to op, share your thoughts)

E - Spiked tail - Cooldown 12/11/10/9/7 - 30/40/50/60/70 mana - 10/20/30/40/50 physical dmg 1.0 AD Swings tail stunning target for 1.1/1.2/1.3/1.4/1.5 seconds (this would be a little long than an autoattack, meaning you have to gap close with void flight then stun)

Evolved - After you use this ability next 3 auto attacks do aoe dmg with bonus 20/30/40/50/60 physical dmg .15 AD(note, this is with your regular autoattack dmg.)

R - Prey Seeker - Cooldown 170/150/120 - 100 mana all ranks - 200/300/400 physical dmg 1.1 AD Globalish range, Dra can only use this ability on preyed targets. The Void Dragons vision reds, as he searches for his prey, which he can then fly onto dealing significant damage. last 5 seconds (passive idea for ultimate is a small increase in damage to preyed target, but less damage to all other enemy champions, give me your thoughts)

Evolved - Grants vision of preyed target, and deal 10% more damage to preyed target during ult duration

Give me your thoughts guys! i want to know if you think its a dumb idea or not. Now when i thought of him i wanted to think of a relentless jungler who is pushed in the direction of camping a lane or counterjungling the enemy jungler. I also thought you can build him like an assassin, duelist, or a bruiser. Even tank would be alright on him.

I could write a lore on him, but im not even sure i want him to be void. he could just be a pissed dragon!

One of my inspirations was this little guy.