League of Legends Jayce, The 100th Champions in League of Legends Abilities Leaked
Passive (both modes): Jayce gains 40 bonus MS and ignores unit collision for 1.25 seconds after each transformation.
Hammer mode (melee)
Q (Thunderstrike): Does magic damage based on X% of target's max hp and knocks away the target.
W (Thunderleap): Jumps to target area, dealing physical damage and applying a slow to all surrounding enemies.
E (Mordin cannon): Transforms into cannon form, gaining increased range and new abilities.
Cannon mode (ranged)
Q (Gate of Speed): Jayce summons a gate boosting the MS of all friendly champions passing through the gate. If Jayce's ranged autoattacks pass through this gate, the projectiles gain increased damage/range/speed.
W (Energy Charge): Jayce overcharges, gaining attack speed for a few attacks.
E (Mordin Hammer): Transforms into hammer form, gaining passive armor and magic resist and new abilities.
R (both modes): Passive mana gain on autoattack, active point blank AoE damage over time.