Some of these ideas remind me of a system I worked out long ago.

Since the monsters and characters could be either living or robotic/mechanical, I had some states that varied depending on the target's type:

Banished: The character is sent to another dimension. Death does not override this particular status. The only way back is to have another character cast a spell to bring the character back or to have an NPC cleric to do it for you. This completely removes a character from the party.
Doused: The character is vulnerable to fire damage. If the afflicted is attacked by a fire elemental spell, weapon, or attack it will do double damage. This overrides any protective gear that the afflicted may have.
Engulfed: The character sustains fire damage (modifiable by armor weakness, absorb, etc.) for a period of time. The character can make no actions during this time, except for Drink or Item. Water spells can cancel the status.
Greasy: For machines (including cyborgs) and characters with Magitek armor, greasy has no ill effect. Otherwise, greasy causes the afflicted to have their weapon strength lowered by 2/3 and their chance to hit is cut in half. Also, their physical evasion is increased by 25% since they are so slippery.
Gritty: Only affects machines. Gritty causes lowered speed and evasion. Also, eliminates chance of critical hits. Wind spells can cancel the status.
Limbo: The character is in an indeterminate state, similar to Banished, but recoverable. The character has 0 hit points, and is uncontrollable. Fight is targeted at a random enemy, but if magic is chosen, spell uses Roulette targeting instead of normal targeting. The item command is locked out, and special attacks target the allies of the afflicted.
Locked: All commands, other than Fight, Magic, Item, and Mimic, are disabled.
Stunned: Character is stunned, and their battle gauge is reset, and that action is lost. Each new turn, there is a 50% chance of recovery, otherwise that turn is lost also.
Tangled: Works just like slow (level 02). The difference is it wears off after a short period of time.
Tiny: The character is small. Derived stats are all considered to be 0. Attack and defense suffer.
Trance: The character is meditating. For one turn, the character tries to restore his/her magic points. If not physically attacked, then the trance will not be broken. A number of magic points = ((Max MP/256) * (Level/8) * [224..255] / 256) + 1 will be awarded. If this is less than 5, set it to 5 points instead.
Wet: The character is soaked with water. This grants a short immunity to fire, as well as a weakness to bolt and ice. This overrides any other armor-given elemental properties. Wet status removes gritty and doused but not greasy. After a short time (12.8 seconds or so), the wetness disappears. Wind-elemental attacks will also remove wetness.