sub 1: echidna obviously
sub 2 (green): asgard, top droid
sub 3 (light): apollo, verche, kirin, Ammy?
sub 4: homuhomu, gigas
for sub 2, asgard is generally better but droid has it's obvious niche for friday dungeons and neptunes. he has low rcv but ecchi and the light sub can fill the void
for sub 3, orb changers apollo and verche are good for killing dark orbs, apollo especially since he has better stats and changes dark+heart, kirin is good for bosses, ammy because its ammy and has >9000 rcv
for sub 4, homu+apollo/verche will get rid of all blue/dark orbs and leave you with nothing but good stuff, gigas can work but then you have terrible rcv. you can try angelion as your green sub+gigas to change dark orbs to fire but eh
you're best bet is probably:
Suzaku, Echidna, Asgard, Apollo, Homura
stats might be kinda on the low side because everyone is low level
if you have a
mikumiku leek then that could replace asgard for lots of rcv but then your HP would be
terrible
