@Teequz
"Ahem, Ratchet casually walks by blackholes everyday. He throws blackholes as frickin grenades damnit."
Which fails to destroy a universe. As seen in the end of Galaxy 1, their black hole was shown to turn into the "Big Crunch" which destroyed the universe. Universe destroying black hole>Ratchet's black hole.
"And Ratchet is completely unaffected by it."
Yeah, by a black hole that fails to destroy a universe. Rosalina on the other hand can just sip a cup of tea while that happens.
"Clank, Ratchets backpack/sidekick, is the keeper of time, and can reset the universe (and destroy it at that)."
When was this again?
Which would do nothing to Rosalina and Lumas since they were shown to be unaffected by a universe being destroyed and reset.
"Nevertheless, resetting the universe doesn't make SSB win the fight, it only resets the universe."
Actually, it does since at the end of Super Mario Galaxy, it was shown to erase an event from happening. I don't see why Rosalina can just use this to erase PS All-Stars from ever existing.
"Check and Mate. Shulk might have godlike powers in this dimension, but what is he going to do when Ratchet sends him to another dimension?"
Shulk can simply use the Monados he gained at the end of the game to come back.
If that fails, Super Sonic can use chaos control to get him back.
"Again, Ratchet is to fucking OP for this."
Not really. Samus seems like a better rival and can actually win.
Being alone, is my greatest fear.