Obryn: The Bloodborne Knight

Passive: Blood Curse:

Obryn's attacks mark their target with a blood curse. Blood curse will automatically proc when the target drops below 30% health dealing 10% of the targets max health plus 50% of Obryn's AD as True Damage. Additionally, Obryn heals himself for 50% of the dmg dealt (dmg and healing cap against large/epic monsters).

Q: Shadow Dash:

Passive- Obryn is light on his feet, granting him the ability to avoid unit collision and gain 3/5/7/9% movement speed. Active- Obryn dashes forward with incredible speed, leading with his blade, Obryn slices all enemy units in his path dealing % AD dmg. If Obryn strikes an enemy champion he may re-cast shadow dash once more within 4s before ability will go on CD (shadow dash resets auto-attacks).

W: Blood Shroud/Blood Price

Passive (Blood Shroud)- Obryn heals for a % of dmg dealt by his spells. Additionally, Obryn can overheal, granting him a maximum of 150/180/210/250 health shield. Active (Blood Price)- Obryn expunges his Blood Shroud dealing a base dmg equal to his shield strength plus % of his AD.

E: Blood Lust:

Obryn's next three AA's deal an additional % of his AD as True Damage, slow the targets movement speed, and heal Obryn for the bonus amount of dmg dealt.

R: Shadow Pursuit:

Obryn vanishes to the shadow realm- becoming invisible for 1s and gaining % decaying movement speed. Holds up to 3 charges. Regains a charge every 30/26/22s.

I like this concept a lot. Even if the numbers don't work out, I enjoy the concept of a bursty mobile jungle assasin.