[Shinzero02]

I'd probably suggest themed packs.
Tech - Lasers, Robot parts, Jetpacks, teleporter effects
Magic - Spell effects, ghost rider skulls, magic artifacts
Ninja Aresenal - Swords, Sai, Shuriken, throwing hand effects
Punisher Arsenal - Guns, Explosives, and accompanying effect parts
X-men - Thunder effects, Ice Slides, Phoenix Wings, Psychic effects. Bamf effects
Web Warriors - Web and Symbiote effects. Spider-Sense effects. Bag Man Heads
Iron Man - various Iron Man suit parts like the floating stuff from Infinity War and Endgame

Body Shoppe troop builder packs: Treat them like the Endgame Team Suit Target exclusive packs and Mr. Fantastic/Super Skrull. One male and One Female generic body with a bunch of accessories and swappable arms and legs. Set them to specific themes.

Dressed for Success: Male and Female suited body options. Maybe have a BAF-esque lower body option for skirt/pants suit options for female characters. Toss in gloved/ungloved hand options and a few generic heads.

Student of X: Reuse/remold the Kitty or Danielle female body, add a generic male outfit too. Give the option for Magik's armored arm, transparent arms, and robotic limbs

School Uniform: Reuse/remold the Stepford body. Provide a male option as well.

Shield Agent: Basic reuse/recolor of the Nick Fury figure for the male option, need a redo of the female body because those were barely poseable in the first place and couldn't even stand well on those heels. Shield theme accessories included.

Body Shoppe Add-on packs:
Mutants - More Multiple Man and Mystique head options. Various mutant heads to accompany the generic body options.

Maggia - generic henchman heads and accessories

Ghost Rider - Male and female ghost rider skulls and accessories to turn any hero figure into a ghost rider option.

Symbiote - Generic symbiote heads, hands and effects.

Tech - more cyborg limbs and accessories. Go here for Reaver parts or Ultron/Sentinel related stuff.