Ways to Temporarily Shut Down (Ex)

[Augment Tab]

Going to be DMing a short campaign here over the next weekend and I have a player that has one of the "you don't age anymore" class abilities (the "Eternal Body" feature of a 9th-level Contemplative, to be specific). I was wondering if there were a way to temporarily disable this class feature, giving them the physical aging penalties and, fluff-wise, forcing them to show their true age.

[Biffoniacus_Furiou]

Trait Removal spell, Serpent Kingdoms, Sor/Wiz 5, living creature touched, 1 hour/level, Fort negates, SR: yes. You temporarily remove one extraordinary or supernatural ability of your choice from the target creature.

Edit: It has a 1 hour casting time, but a Wizard with the feat Uncanny Forethought in Exemplars of Evil can cast it as a standard action or a full-round action.

[deuxhero]

Short of level draining you to before you got the feature, none that I know of.

Plenty of (Ex) abilities have ways to shut them off (Fatigue a Barbarian and no rage) and I think some racial (Ex) abilities are lost under polymorph effects but I don't know of any way to shut down (Ex) in general or to remove Timeless Body.

Even if you did remove it, penalties are gained when you hit age thresholds, not "being old". May combine it with magical aging I guess.

[JusticeZero]

You could also get away with using a custom effect to do it - just write up a spell that has that effect, and give it to someone; it's not exactly an unbalanced effect in relation to all the other save-or-suck spells available.

[Augment Tab]

You could also get away with using a custom effect to do it - just write up a spell that has that effect, and give it to someone; it's not exactly an unbalanced effect in relation to all the other save-or-suck spells available.

I could, but I wanted to see if there was something available that I could use before resorting to homebrewing something. Biffoniacus_Furiou's suggestion will work nicely. Thank you to everyone who responded.

[Crake]

you are aware that when they regain the class feature, they'll keep all the penalties you just gave them, since the ability specifically says it doesn't undo aging penalties, and the class feature will have essentially become useless for the span of your short campaign. If the fact that they are getting free aging bonuses without aging penalties is something you dont like, then just tell them that they cant start off venerable or whatever.