A F2P in need

>Raikou-Jalter-Dantes and is F2P

You're lucky as hell, dude.

Want some advice?

First, your Buster lineup is excellent, extra kudos for mostly being females, eligible to use the buster dmg bonus CE. Half of the bosses (the ones weak to buster) are screwed with you combining Kaleido Ruby CE on them.

Lancer Alter will deal with the normal "final" boss, who is an archer weak to buster dmg, just fine.

Your only problem is your best Rider being Quick NP based, as they got no bonuses, like, at all. Also, your strongest Arts units are an assassin (class disavantage) and a Caster, whose NP does no damage.

So, the supports you should been look for are offensive arts females, specially Riders, like maxed Surf Mordred, or if you really want to smash everything even faster, a maxed Medb, who get class advantage against the majority of the bosses, plus a 50% event bonus damage (and she is a ST NP Buster).