Yeah sure, i think rainbowdecks are the most fun and versatile decks around.
It just seems to be so fragile when it has to play against certain decks. It's to easy countered. An early black hole is like instant gg. On the other hand i get often killerdecks with tons of damage, too.
Maybe i was just unlucky, maybe i played wrong or i just gotta play around with other cards to match it my playstyle
kim, not really ineffective, just instable. Every deck has a "worst case enemy" that can counter. It's just frustrating to get slowly killed in silver league by an almost unupped standard-mono-aether or having some black holes that force you to give up.