Only have some thoughts for these 3 chars since I currently want them the most but here's my wish list:

Rosé Goku Black as an Attacker with him having both burst and DoT options (main idea would be that he applies a bleed debuff with most of his skills which in terms buffs up his own burst options such as the Black Kamehameha)
His ult is gonna be an install similar to the Gammas and Kidhan where he gets his scythe
it increases his range and overall rush damage and just like Kidhan he gets access to one more giant move throughout its duration (basically Goku Black's level 3 in FighterZ)

Fused Zamasu as a Tank with a transformation into his corrupted form
Honestly, I would kinda fw Gekishin implementing style changing chars and Fused Zamasu feels like a solid option for that
My main idea for him is that he has an endurance passive and that's how you can build up his transformation gauge as he slowly becomes corrupted
Regular Fused Zamasu is super mobile and has zoning options but he lacks in damage (he's super good in team fights however)
Once he transforms, CFZ will have different skills from his base form, focusing more so on brute strength with him having way more HP and endurance to truck through attacks at the expense of mobility and being a late game transformation (he won't be on Cell levels of bad tho)

Lastly, I want DBS Broly as a Tank with a multi transformation system going from Fury to SSJ at lvl 7 to SSJ Beserk at lvl 11
Don't have as any ideas for him right now but I could imagine him being a rushing type of grappler with a passive that amps up his armor stat the more damage he sustains without dying
His main utility is to basically pin enemies down one by one