This is kinda obvious but Ruby thinks the omnitrix is just the coolest she’d love to fiddle with it but ben tells her the story of how he almost destroyed the universe when he was 10 because he pressed the wrong button and she decides she’s only going to admire it from afar
Yang immediately acts like the typical overprotective older sister. It scares ben at first because even though he has the omnitrix, she’s Yang. But they actually warm up to each other pretty quickly after Ben shows her Upchuck and she cheers everytime he destroys something
Ruby is always up for modifying literally any electronic ben owns that she has a vague understanding of. She modified his timecycle without him knowing for the sole purpose of equipting it with speakers that loop applause for like a minute whenever he does something cool
Ruby is slightly afraid of going offworld just because seeing an alien world seems like it’d be really disorienting, but Ben offers to take her with him whenever he goes on a plumbers mission or etc. even though rook thinks its a bad idea (her coming along, that is). She generally makes some sort of excuse and then kisses him and wishes him luck. She helps a lot on earth, though.
Ruby modifed her scythe a little so it has the omnitrix sign on it when she uses it. Ben has a pin of her scythe with a rose symbol in the background on his hoodie. Ruby would have gotten a pin, but she thought it looked better on her weapon
Ben tries to make cookies for Ruby but ends up burning the kitchen. Ruby gets pissed at him but Ben can't take her seriously because she sounds like an angry kitten.
ANGRY KITTEN RUBY awwwww -w-
Although I’m not sure if Ruby would react with a bunch of anger over that… wait what if it was Weiss’s kitchen and Ruby starts panicking when she sees what happened because Weiss is going to KILL BEN and PROBABLY HER BY EXTENSION
Ben goes XLR8 and they both use their super speed to try and clean it up but it doesn’t really work (you can’t un-burn a room by moving stuff around) so when Weiss finally shows up they make a break for it