>>712924158I think the idea is that these are basically some sort of symbiotic organism made from multiple independent individuals connected together, kind of like a cellular colony except at the macro level. Each one is an independent individual, but they normally and naturally live as part of a multi-body entity.
So most likely you'd become one of them, and be expected to live merged with the others, which sounds like absolute ass.
That or you somehow replace ALL of the individuals and just get to live with like 6 or 12 eyes or some shit, which would be weird but not quite as bad. But I don't think that makes much sense. Ultimately I think becoming one of these pokemon just doesn't make sense at all - some creatures are just too vastly different to have a sensible transformation into.