Talk:Helena Blavatsky/@comment-35224254-20180405173419/@comment-30043476-20180413123509

Helena when you need damage and NP charging, Hans when you need healing and defense. The harder and longer a fight, the better Hans is as an option, the shorter and easier the fight, the better Helena is as an option.

This is due to the fact Helena has a more accessible and reliable damage boost (20% boost on her skill rather than 25% boost on a NP, no RNG chance for it to fail), her NP deals damage itself and she can boost the teams NP gauge allowing other members to more easily NP. But she has long skill cooldowns and offers nothing in the way of defense or sustainability, so once cooldowns are exhausted and damage is dealt, if the boss isn't dead, she starts to contribute less and less for several turns.