By Newtorious: Charge skills on floors 1-5, can pop dragon skills to help beat the serpents (even if all three attack at the same time you'll be fine. The team recovery is huge and you have several turns to heal). Pop DAL to kill the light Carbuncle, pop WAA's counter to help out with the last Carbuncle. Six turns or less ftw
By dashti: Stable build+orb changers. Always keep health full, and eliminate same-turn enemies. For serpents, get rid of one of the same-turn ones first. For carbuncles, doesn't really matter. If you're worried about health, get rid of light first (although water dies faster). Can sub Asgard (mainly HP) for mainly ATK+RCV wood monster.