User blog comment:Alb3rtusja/Can't use my Magica party - -/@comment-3215051-20161109051709/@comment-28010705-20161109102139

Some additional information to Kodachi's ones:
 * "You can't have characters like Hero (Ultra Rare) in the party if Hero (Rare) is on an expedition." --> In general: same character with different rarities (it occurs to me with Envy)
 * Chain ability is sometimes named kizuna.
 * [Not the case here] Some quests have pre-requisites ; by selecting a team, a pop-up message will occur if you don't reach them.

PS: Grats for your Collab team!