(AoU) Giant Man: Pym Particles

The ability text states: "When Giant Man attacks, you may reroll him. You may return him to his original face."
I understand the timing of this, and what it means. I know that the aim is to get a second chance to get him to his Level 3 face if you didn't get him there the first time.
However, if you were to roll him onto his (M) or (MM) face, can you return him to your Reserve Pool as usable energy for globals? Or would you have to just reset him back to his original character face?
Sorry that it is a bit corner case, but this came up in a game I was playing and none of us knew how to rule it.
Any information you could provide would be greatly appreciated.
I understand the timing of this, and what it means. I know that the aim is to get a second chance to get him to his Level 3 face if you didn't get him there the first time.
However, if you were to roll him onto his (M) or (MM) face, can you return him to your Reserve Pool as usable energy for globals? Or would you have to just reset him back to his original character face?
Sorry that it is a bit corner case, but this came up in a game I was playing and none of us knew how to rule it.
Any information you could provide would be greatly appreciated.