So your PC's can expect to get hand swarms attacking them?If I was DM to such a character, I'd definitely be looking for an excuse to make that a thing. Just like I always try to start taking hands as soon as the Cleric gets Regeneration. A character facet that goes un-used is boring!
The first one was OK, I liked the second one better. My inner geek started correcting you once I read this. Basically, there are aliens, their tech is the guyver suits.(A bio-mech suit that is stored in a pocket dimension when not worn).That sounds very similar to a movie called Guyver (I think?), it was about bio-armor suits made by some Evil Corp that would bonds with their user. The hero got one that was free somehow and was also the strongest, so he had to use it and bring the bad guys down. Great movie from when I was a teen, wonder how it'd stand up if I tracked it down ...
The company was run by the conspiracy Chronos, a group made up of zaonoids(humans with a monsterish battleform). They were also made up by aliens.
The aliens went away for a long while. And the story in both anime/manga/movies starts without them being around.