LoL Champion Build Guides: Senna

Senna's basic attacks on-hit and damaging abilities on enemy champions apply Mist for 4 seconds, refreshed to 0.75 seconds if Senna starts winding up a basic attack on them. If Senna applies Mist to the same target twice, she collects it, dealing 1−16% of target's current health as bonus physical damage (depending on level), and making the target immune to further Mist applications for a few seconds.

Enemy units that die near Senna have a chance to spawn a Mist Wraith for 8 seconds, increased to 2 Mist Wraiths for epic monsters. Senna can basic attack or use Piercing Darkness or Dawning Shadow against a Mist Wraith to destroy it, gaining 8 gold and collecting its Mist.

Enemy champions, large and epic monsters are guaranteed to give a mist. Minions and lesser monsters that Senna kills have a 4.166% chance. Large minions that Senna doesn't kill are guaranteed, while lesser minions and lesser monsters that Senna doesn't kill have a 28% chance.

Each stack of Mist grants Senna 0.75 bonus attack damage. For every 20 stacks, Senna also gains 25 bonus range and 10% critical strike chance. Upon exceeding 100% critical strike chance, Senna converts 35% of the excess into life steal.

Senna's basic attacks deal 20% AD bonus physical damage on-hit and grant 10 / 15 / 20% of the target's movement speed as bonus movement speed for 0.5 seconds on-hit.

On-target Cooldown: 6 / 5 / 4 (at level 1 / 6 / 11)