*Cracks Knuckles Arcee wasn't really slimmed down. She's sill relatively the same size (galvatron was almost twice her size even in the flashbacks) she just sized down her shoulder pads. She wasn't particularly wider or more built up than she is now. Maybe she was thinner in the Milne design or on some covers, but not for a long time. Galvatron had magical evil powers when they needed the matrix to beat him. And she, Optimus and Soundwave all needed to team up to kill him, AND he's her brother who she knows well and has been fighting for millions of years. She specifically acknowledged her guilt and her rapport with Prowl was that he was trying to manipulate her while she was trying to change who she is and be LESS sarcastic and violent. Okay, bud. BONUS: She's very clearly set up as a friend and mentor to Aileron, which is who I was referring to with the "big sister" thing.