From Worlds Collide Wiki - Final Fantasy VI Randomizer
Bug Fixes

Enemy Damage Counter (-fedc)
If enabled, fixes a bug causing enemy damage counters to trigger if the enemy takes zero damage or is healed after the first time they lose HP. Otherwise, after the first time an enemy loses HP their damage counters will be triggered by all attacks. Notably, this allows players to cast Scan on MagiMaster after WallChange without triggering another WallChange.

Evade (-fe)
If enabled, fixes a bug causing the magic evasion stat to be used instead of evasion and restores the intended effects of statuses such as blind and items such as beads. Otherwise, the evasion stat will have no impact.

Boss Skip (-fbs)
If enabled, fixes a bug allowing players to skip the Inferno and Poltrgeist bosses in Kefka's Tower. Otherwise, the bosses will be skippable.

Vanish/Doom (-fvd)
If enabled, fixes a bug causing death immunity to be ignored when a target is vanished. Otherwise, death attacks will always succeed against vanished targets.

Jump (-fj)
If enabled, fixes a bug causing characters to disappear as a result of jump/super ball/launcher interactions. Otherwise, the bug may still be triggered.

Boss Restoration

Restore Undead Bosses (-bnu)
If enabled, GhostTrain, Hidon, Hidonite, and SrBehemoth will be undead, and therefore vulnerable to Revivify and Fenix Down. Otherwise, these bosses will not be undead.

Chadarnook Less Demon (-cmd)
If enabled, Chadarnook's conditions for reverting to painting form are not modified. Otherwise, Chadarnook demon form appears for longer and does not immediately switch back to painting form.

Specifically, Chadarnook originally switches back to painting form after ~40 seconds have passed or being attacked 5 times. However, after switching forms the other condition is not reset. For example, if 39 seconds pass and the player attacks 5 times then the next time Chadarnook appears in demon form it may immediately switch back to painting form after only 1 second. Disabling this flag resets both conditions when changing forms and also increases the timer threshold to ~48 seconds and the attack threshold to 6.

Doom Gaze Escapes (-dgne)
If enabled, Doom Gaze can escape and be escaped from and will be excluded from any shuffling/randomization options (i.e. will only appear in the WOR skies). Otherwise, Doom Gaze does not escape and cannot be escaped from, and may be shuffled/randomized into the general boss pool depending on other settings.

MagiMaster Casts Ultima on Death (-mmnu)
If enabled, MagiMaster will attempt to cast Ultima once defeated. Otherwise, MagiMaster does not cast Ultima before death. Note that this Ultima cast will be affected by Ability Scaling, if that flag is enabled.

Wrexsoul Casts Zinger (-wnz)
If enabled, Wrexsoul will begin the battle with Zinger and possibly use it throughout the fight. Otherwise, Wrexsoul does not use Zinger to possess a character until they expire.