These are some of the states for my upcoming project "Plantera Adventures" (which i am yet to post). All of these are done with editing certain scripts such as Game_battler, Game_unit and Scene_battle and some additional scripts.
Undead - Cannot be healed, affected becomes weak to the "Light" element.
Death wall - When affected is damaged, the affected gains death status.
Alma barrier - Affected is protected by a barrier that will reduce all damage to 1. The barrier is broken when damaged 4 times and is followed by an explosion effect and a message "Alma barrier destroyed!".
Frozen - Affected cannot move for 3 good turns and affected battler's sprite is encased by ice via animation. Is cleared by a fire elemental attack.
Delirium - Targeting goes haywire. The character may still choose skills as usual but ally hitting skills will hit enemies and enemy hitting skills will hit allies. One of the most dangerous statuses if not dealt with immediately.
Restrained - All physical attacks are disabled.
Erased - Gained by enemy attack "Eliminate" and "Warp". Removes target from battle, sprite disappears and affected becomes untargettable to enemies and to allies for the duration of the battle. Affected is flagged as dead, HP and SP however is retained.
Possesed - Is associated with the enemy skill "Possess". The user of the skill disappears from battle and inflicts this state on a random character. The enemy that has used this skill cannot be defeated until those who have been affected by this state is killed off (a job to be done by your party) so that the user may return to battle to be defeated.
Infection X - Same as Zombie of Final Fantasy. Affected's HP drops to 0 and starts attacking either enemies or allies each turn. Aesthetically, they turn green and show an angry speech bubble.
Fossilized - Affected is flagged as dead and become invincible to attacks and takes no healing. Same as petrify. Aesthetically, the character's sprite turns grey.
Blown away - Dealt with enemy abilities "Blow" and "Snuff", it ejects a target from battle. If the remaining party members are killed off (death, fossilized or Infection X) or the entire party is blown out, the battle ends with a draw and is neither a game over or a victory. The party gains no EXP or rewards.
Of course there are many more.