I'm more of a mind of something RDM native that isn't fully preventative of TP moves.

Stun stops an action, and as soon as it ends, it can just try again. That's why Chainspell Stun is so necessary in some situations, and mobs who do multiple TP moves in a row can get quite annoying.

I'd prefer an ability that sort of sweeps the legs out from under the monster and force it to loose its TP for a reduced or even zero effectiveness, more akin to flash in that regard, where you can watch a lower NM completely whiff a powerful TP move, but I would like to see that applied magically as well as physically.