Good idea here. Weapons which are OP but give the enemy an advantage would add new strategies to the game. In one of my posts (can't remember which ) I had an idea for a cryo-launcher which reduces movement speed and damage of the enemy, but for the cost of reducing the enemy's heat.

Windu's light saber: Side weapon: weight 75 Electric damage 10, energy drain 50, -5 electric resistance Explosive damage 10, heat damage 50, -5 explosive resistance uses 2
User repercussion: -25 energy +25 heat

Leonardo's sword: Side weapon: weight 75 Physical damage 100-200, -10 physical resistance uses 2
User repercussion: -25 energy +25 heat

Gundam chassis: Torso: weight 500, 500 health, 250 energy 100 regeneration; 250 heat 100 cooling; bullets 50, rockets 50; 10 electric resistance, 10 explosive resistance, 10 physical resistance.

Lightning generator: Top weapon: weight 100 Deals electric damage equal to opponents maximum energy, leaves opponent with no energy and disables regeneration for one turn. Uses 2. Range 1.
User repercussion, uses energy equal to damage done.