I am wrong about the power roll. NO excuse. i was wrong. about the veil being a passive attack. ok i will not argue that.  but in the games i played i we gave a player or monster a chance to beat the veil with a automattic roll. a different way to do it is to say for the veil to work is for it to be stronger than the monsters alertness, lore, or whatever you think it should use to see through the veil. if monster has alertness, lore, or whatever at let say 4. the player a veil of 5 or better to hide from the monster. then on the monster's turn it could roll to find the player. hope that made cents.

In my mind a veil is a attack that does not hurt the monster. OK. let try to pin down what i am saying better.  if a player wanted to cast veil. the player would roll conviction to power the spell, discipline to control the spell. if the player won the rolls now the player casts the spell. ok the veil is on and run BUT did the spell fool the monster. the monster would roll to dodge/block the veil. (if the player cast a fireball. the monster would roll to dodge/block the fireball.) now for the monster to dodge/block the veil what would the monster roll? alertness, investigation, or lore. i say let your Game Master decide. now lets say the monster failed to dodge/block the veil. now it needs to find the player. the monster rolls to find the player. what does it roll? again let the Game Master decide. let us say the monster found the player but now it is the player's turn. so what does the player do? let us say recast veil and start it all again. that is basically what happened to molly fought the ik monster (Ik'k'uox was it's name i think) in the 12th book Changes. hope that make what i am saying clearer.