FAQ
Q: What, exactly, is a duo/trio?
A: A duo is a deck that uses cards from two different elements. That includes pillars/pendulums, but not mark or abilities. A trio is the same, but with three elements.
Q: Why is this and this banned?
A: Because otherwise you would either have to use it or suffer. With the most overpowered cards in this setup banned, you have to get more creative.