When gaining bonus range when going through Acceleration GateShock Blast is simply re-targeted so as to reach a location further along its travel path (but further away from Jayce's original position) ignoring any range calculations whatsoever.
Shock Blast briefly grants vision of the area it explodes in.
If the enemy dashes at Jayce whilst Jayce is channeling Thundering Blow, they will get knocked back and travel the distance they have dashed as well as the knock-back distance provided by Thundering Blow.
Just like with HeadbuttThundering Blow's target is 'stunned' until they travel the entire displacement's distance, even if they hit terrain or structures along the way.
Hammer Stance - Active:Jayce transforms the Mercury Hammer into the Mercury Cannon, gaining new abilities, ranged attacks with 500 range, and causing his next basic attack to reduce his target's armor and magic resistance by 10 / 15 / 20 / 25% for 5 seconds.