ToME: the Tales of Maj'Eyal

create a debuff for being the target of a Displacement Shield.
1. people can know they are being the target.
2. people can remove the displacement shield by use remove magical effect methods.

It would be nice to know when some rare or boss has a Displacement Shield targeted on you. I don't really like critting myself for 400 damage and not realizing it

"You look at X with murderous intent, but get a weird tingly feeling at the back of your neck..."

I suspect that's the way nethack would do it, at least.