Luden's Echo

2750
1925 (70%)
100 ability power
600 mana
10 ability haste
Passive
Unique – Echo: Gain 6 Echo stacks. Dealing ability damage to an enemy consumes all Echo stacks to deal 75 (+ 5% AP) bonus magic damage to them and, for each stack consumed beyond the first, an additional enemy within 600 units of them, firing an orb at each secondary target that impacts after 0.528 seconds to deal the damage. If the number of additional targets fired at is less than the number of stacks consumed, deal an additional 15 – 75 (based on remaining Echo stacks) (+ 1% – 5% AP) magic damage to the primary target, for a total of 90 – 150 (+ 6% – 10% AP)  deal an additional 20% damage to the primary target for each remaining Echo stack  (12 second cooldown).
Limitations
Limited to 1 Luden's Echo.