Champion Concept

So it just happened I felt like creating an idea for a new champion. Since there are way too many concepts here, I hope it isn't similar to an existing one. Also I tried to balance the numbers out by comparing several stats on existing champions, so I hope its neither OP nor UP. Feel free to comment if it sounds interessting or if something is a total no go and stuff like that. And btw, since english isn't my native language be gentle about mistake I may have made.

Championname: Nirvan the Cry of the Banshee

Main Role: Assassine , Secondary Role: Mage Melee: Attack Range 150

Base Stats Lvl 1 - 18:

Health: 520-1900 Mana: 300-1300 AD: 57-130 Armor: 28-77 Movement Speed: 345 Health Regen: 5-15 Mana Regen: 5-17 AS: 0,6 MR: 30-49

Passive: Aura of Despair

Enemy Units who are silenced take 0,5/1/1,5 % of their max health magic damage every second as long as they are within 700 range of Nirvan.

Q: Desperate Fate, 675 Range, 50/55/60/65/70 Mana Cost, 12/11/10/9/8 seconds CD

Nirvan marks an enemy Champion for 2 seconds foretelling their death, silencing them for 1 second every time they cast an ability while marked. If the enemy is already silenced, the mark will enlenghten the duration of the silence instead, dealing 50/80/110/140/170 + (0,3 AP) magic damage.

W: Curse of Menace , 1000 Range, 1700 Missle Speed, 50 Mana cost at all ranks , 14/13/12/11/10 seconds CD

Nirvan throws his daggers into a targeted direction, dealing 40/70/100/130/160 + (0,3 AP) physical damage if they hit an enemy unit. If the target is silenced the next use of Song of Stillness has 450 range and will make him appear behind the target, granting him 15% additional spellvamp for the next 2,5 seconds.

E: Song of Stillness , 250 Range, 60 Mana cost at all ranks , 8/7/6/5/4 seconds CD

Nirvan attacks the vocal chords of an enemy, dealing 80 (/110/140/170/200) + (0,5 AP) magic damage as well as silencing them for 1 (/1,2/ 1,3 /1,4 /1,5) seconds. Enemies who are already silenced take additional 30 (/40/50/60/70) + (0,1 AP) physical damage.

R: Dance of Malice , 450 Range, 125/175/200 Mana Cost, 120/100/80 seconds CD

Summons a Banshee wherever Nirvan stands which releases a bloodcurdling scream dealing 175/230/300 + (0,7 AP) magic damage in an 450 range Radius. Enemy Champions hit by the soundwave are silenced for 2 seconds. Dance of Malice ignores 50% of the enemy magic resistance if the enemy is already silenced.