Forms and stages
Normal SSC forms progress from stage 0 to stage 4. Experience unlocks stages, while the form's environment and instinct rules determine whether progress can continue. Stage 4 is the usual entry point for SSCA endgame branches.
Stage changes can alter health, movement, abilities, equipment slots, and resource bars. A transformation is not automatically an upgrade: read the restrictions column on the form page before choosing a route.
SSCA forms are special forms. They generally carry NoInstinct, NoCursedMoonEffect, SpecialForm, and InhibitorImmune, so normal stage progression and ordinary inhibitors do not apply.