Board Thread:Questions and Answers/@comment-108.233.103.146-20150607225812/@comment-112.209.82.46-20150609105535

Element buff leads are still usable but there are other units with better lead skills. I just prefer BB spamming over power for general content which is why I suggested Uda as your lead. Ophelia is not that good for pve because her BB dmg multiplier isn't that strong but she's great for arena.

Rainbow teams are making a comeback :) Quaid has the best rainbow lead skill I've seen in global "100% boost to atk if 5 elements, reduction in BB gauge required, boost to BB fill rate." It all depends on the units you have at the moment. The game has more than just mono and rainbow teams. Meta players now consider the buffs each unit can give to your squad and how it synergizes with other unit lead skills/BB's/Spark timing. Meta teams try not to have units that have the same buff types (it's like having two healers in one squad)  unless one of the units has something that the other doesn't.