Absolution

When an enemy dies near Senna, a soul is left over. She can attack the soul, which will then increase the power of her relic cannon with increased attack damage, attack range, and critical strike chance. Auto attacks and abilities apply mist on an enemy unit for 4 seconds. The next auto attack or ability deals 1 − 16% of the target's current health in bonus physical damage (at level 1 - 11). For every 20 stacks, Senna also gains 25 bonus range and 15% critical strike chance. Once you get 100% critical strike chance, Senna converts 35% of the excess into life steal.

Piercing Darkness

Cost: 70 / 80 / 90 / 100 / 110

Senna fires a beam of light through a target. It heals allies within the beam for 40 / 60 / 80 / 100 / 120 (+AP) (+4 AD) and damages enemies that are hit for 40 / 70 / 100 / 130 / 160 (+25%)(+4 AD). Auto attacks reduces the cooldown of Piercing Darkness.

Last Embrace

Cost: 50 / 55 / 60 / 65 / 70

Senna throws out a projectile, hitting the first target hit for 70 / 115 / 160 / 205 / 250 (+0.7% AD). After a second, it roots the target and other nearby enemies for 1.25 seconds. The duration increases by.25 seconds when leveled.

Curse of the Black Mist

Cost: 70

Senna turns into a cloud of mist for 6 seconds and becomes a wraith. Allies that enter the mist are camouflaged. When they leave the mist, they become wraiths, which gain 20% movement speeds. Wraiths are unselectable and their identities are hidden unless an enemy champion is nearby. The duration is increased by .5 seconds when leveled.

Dawning Shadow

Cost: 100

Senna fires a global beam. Enemies hit in the center are hit with 250 / 375 / 500 (+1.0 per bonus attack damage) (+50% of ability power). Ally champions on either side of the beam gain a shield, which allows them to absorb 120 / 160 / 200 (+40% of ability power). The shield's power scales based on the amount of mist Senna has collected.