Garcin wants in on the action, and he suggests a second magi come along to back up Frederic. After all, there were two pirate ships, thus the group might theoretically need to split.
I think it would be a good idea for Antonius to go, as he can probably protect the crew from the influence of the pirate queen. He can also see regios easily, to that will surely help.
I dont want to play two characters, so anybody that wishes so can play Vincente.