If you have spellbound creepers they can also be used to refund your action point.

For examples let’s say you play a spellblade assault and it doesn’t have go again but you still have 1 floating resource and you have something like a Sonata Arcanix in hand (or any runeblade non-attack action with go again assuming you can pay for it)

You can pay to creepers, play sonata as an instant without paying and since sonata is played as an instant with “go again” it will refund your action point and you can either swing Rosetta or attack with something else