I think it would be nice if a builder can get more than 11 elements.
My idea is:
A builder can summon a boss to the other opponents.
If the opponent is able to beat the boss, the opponent builder gets an element of his/her own choice.
If not, the builder who summons it gets an extra element of his choice.
The level of the element that can be chosen must comply with some rules.
Each builder can only use the skill once.
This is just a general idea.