1. Idea: It´s not allowed to make creatures or weapons with skills immortal.
2. Idea: unupped , exactly 60 card , no Novas, Immolation, Quantum Pillars, Devourer, Earthquake
3. Idea: unupped, Trio Decks (3 different colors min / more than Trio , No Quantum Pillar, Novas, Immolation, Devourer, Earthquake ( people shall be able to play all of their colors, but not more).
4. Idea: no pillar allowed, upped cards possible.
5. Idea: low cost (high cost) decks. cards may not have costs > X ( <X).
6. Idea: MtG version: only 4 copies of a card allowed, 60 cards (?), only Pillars may have more than 4 copies. Quantum Pillars only 4, because Rainbow Decks would have an advantage here.
P.S. I´m not one of the MtG players, I´ve only read some rules.