While fighting the Roarmulus Twins, at the very beginning of the battle when the screen turns yellow to start the fight, I used my Seraphynx's first skill. Afterwards, it just disappeared after making its attack sound.
She came back on the next floor.
my bug in here is when i walk in button before fight RT... my wing and tail gone --a but back again when out from arena after beat RT. hmm maybe just my camera view~ but anything can happen in RT, i got most bug in here and meet gm alot here.. from trapped in wall to switch not working~