Small question about this card

So, the letter says that I can exchange my Bakugan for another quality version of the same type...

(Example: Dragonoid for Delta Dragonoid )

But it doesn't say where this Bakugan need to come from. This leads me to think that I could just take any other version of Dragonoid from my collection and swap it, cause again, the card doesn't say that it needs to be one of the Bakugan I'm using in the game... I think it allows you to get this Bakugan from anywhere (except from the opponent of course) otherwise it would say "from the used - unused pile"

But another point that comes to mind is:

I have a Mutant Helios, with half a Mercury Dragonoid. These Bakugan are combined so could I use this card to trade my Mutant Helios + Mercury Dragonoid for another Dragonoid??? 🤔