His lightning abilities had under major changes; they had gone from being buffs to being active damage-dealing spells. He could now release the electricity generated from his body like a bolt of lightning, dealing both physical and stun damage to the target.
The chances of getting stunned were dependent on the target's resistance and one's resistance to an element was dependent on his/her level and element.
Compared to other elements, aquamancer had the lowest resistance to lightning-based abilities meaning he was their bane.
If the target wasn't stunned on the first try, the stunning effect was able to stack up. That meant even if the target had a high resistance either because of his level or his element, it would only be a matter of time till he/she was stunned as long as they kept being hit by lightning.
While familiarizing himself with his powers, a thought came into his mind causing him to pause and try it out.