Since a lot of Granblue card return from the drop zone it shouldn't be too hard to get the rrestraint off of this card. A lot of cards that do return require you to retire one of your other units. Retire the units that you can easily user as fodder, i.e. ones you don't care about or ones that can resurect themselves (removing restraint on a future turn). Also as it states in the rulings page for this card if it is brought back from the drop zone by a card's effect (Death Seeker, Thanatos, Witch Doctor of the Abyss, Negromari etc) it loses restraint until the end of the current turn. Also remember that if it is your vanguard it gains and extra +5000 if it is boosted by a Granblue.

If you really want to get rid of it you can use it as fodder to resurect another unit...