A void worm with multiple build paths, champion kit

Q Spits puke onto target location, think xerath w but bigger and with a cast time that makes it inneffective for fighting an enemy that has reached you. It deals flat magic damage, slowing enemies hit by 60% for 3 seconds and leaving a 30% slow in the area for 3 seconds. costs 90 Mana. 90 % ap scaling.

W makes 'void worm' bite and hold onto his target, dealing small % physical damage, slowing the target by 25%. void worm follows(think reverse skarner ult) his target for 1.5 seconds, stunning for 2 seconds and doing flat physical damage if he is not interrupted by hard cc or killed. Void worm cannot cast other abilities while target is ensnared. Costs 70 Mana. 135% ad scaling on the damage that procs with the stun.

E Spits puke as a short range projectile, dealing % magic damage, blinding and silencing the target hit for 1 second. Costs 40 Mana. 80% ap scaling.

R Targets an enemy champion and after a 1.5 second channel void worm burrows underground reemerging 1 second later at the target, knocking up the target for 1 second and dealing flat physical damage. The channel can be cancelled by hard cc. Costs 100 mana but refunded on channel interruption. Cooldown of 5 seconds if interrupted. Costs 100 Mana. 120% ad scaling.

Passive. Q and E mark enemies. If Void worm auto attacks or w's a marked champion he restores mana. Marked enemies take %magic damage over time(no stacking).

The ult is like VI's but with an interruptable channel, and removes you from the map while channeling. It would reward flanking and help chase enemys down. I think the trademark ability of this concept w, is great, the scaling is very high yes, but it is preventable by hard cc and gated by cooldown and time to proc. The purpose of the passive is to allow him to fight but make it difficult to litterally spam abilites at range only without building for it. He should have low base mana regen. If this champ was made he would be played in the jungle and top lane.