"We will see whose belief is stronger."
Name: N
Ability: After using attacks that are super effective against the target, this trainer's Pokemon gain 1/8 of the damage in HP dealt.
Explanation: Essentially Shell Bell's effect but only on SE attacks. Using SE hits is meant to reflect N's use of all 17 types (at the time of BW) while the recovery represents how much N cares for Pokemon.
"I was expecting exactly that kind of move!"
Name: Ghetsis
Ability: When this trainer's current Pokemon is damaged by any move, X starts at 0.2. Moves used by the current Pokemon have their damage multiplied by 1+X, and whenever the current Pokemon is hit by the opposing Pokemon, X increases by 0.2, with a maximum of 1 (this means 1+1, a final multiplier of 2). X resets to 0 when this trainer's current Pokemon is no longer active.
Explanation: I know that looks like a whole lotta maths and no one likes maths but basically Ghetsis' current Pokemon will get a 20% damage boost every time it gets attacked and that damage boost caps at 100%, resetting when switched out or KOed. Think of it like GSC Rage but weaker and it's for every move. This is meant to reflect Ghetsis' abusive nature (not only to N but to his own Pokemon, his Hydreigon in B2W2 has 0 friendship and uses Frustration) and his own unbridled rage when confronted in B2W2's climax.