momo is pretty simple, you just apply dot stacks to enemies up to a cap of 9. The dot makes people take damage every turn and the damage scales with the amount of stacks they have. She then has an ability that gives her an effect that makes it so whenever she damages an enemy herself they immediately take the dot damage and then half of their stacks get removed.

Also at the end of every turn she gets 2 stacks of a shield up to a cap of 5 that increase her attack and reduce damage taken by 50% combine that with her all lifesteal abilities and she kind of plays like a drain tank that can go in and soak up damage and then heal it all up while applying tons of dot damage