How to adjudicate this situation?
They're on an 8' wide bridge, no railings. A mind flayer has thrown a smoke grenade, making two squares totally blocked as far as visibility goes. The whole place is swarming with bats with whom the mind flayer is telepathically linked.
A monk character is on the other side of the smoke. He has announced he is running through it. He will be blind, but only for 10'. The mind flayer sees what the bats see, and because of their sonar (i.e., blindsense), he at least knows the monk is running through.
If he attempts to trip the monk, what bonuses, if any, should he get?
He does not actually Get any Bonues.
If the Monk is still blind when the Trip attempt is Made then he gets penalties. Essentially looses his Dex and Dodge bonues to CMD for being blind.
Which if your fighting mind flayers could be a drop of 8 or so pts to his CMD