Lane sustain and late-game scaling.
Improved attacks and sustained damage
Attacking and moving builds energy stacks. At 100 stacks, your next attack heals you and grants increased MS.
Takedowns restore health and grant bonus gold.
Takedowns on enemies grant permanent Tenacity.
Deal 7% more damage to low health champions. Gain AD/AP after kills or assists.
Burst damage and target access
Recover health when you damage an enemy champion.
Heal for a percentage of damage dealt with your abilities. Increases with each unique takedown.
Offense
+5 AD or 9 AP
Flex
Defense
+6 Armor or 8 MR (match-up)
Fleet Footwork is excellent for lane phase health sustain as well as massive late-game teamfight healing.
Triumph's mid-fight burst heal allows you to pop off in teamfights with mulitple kills with [R].
As a melee mage Tenacity goes a long way in providing you safety from early ganks before 6.
Coup De Grace's execution damage synergizes well with your heavy scaling and reset based teamfighting.
Taste of Blood further improves your lane phase health sustain for early trading.
Ravenous Hunter will grant you a ton of teamfight health sustian so that you are able to get multiple casts of you [R] off without being killed.