EVOKE gives the Monk a Camouflage like adaption to their surroundings-- an elaborate smoke show happens along with the use of a magical orb which is generated from the palm and erupts between the foe and the Monk! This gives the Monk a perfect hide with a +20 to their UAF and a +40% chance to Tier up from the successful Ambush. I imagine if it's only a couple of mana then the advantage could be a bit lower. Also if there was a light daze/stun effect going on (something like a stance push up before the push down, a kneeling/dropping, a stun/dazed thing ) which would be able to end just after the 3 seconds to cast the spell, so a 4 second stun or whatever so if the Monk seizes the timing advantage they can get them while they are still stunned.

CHANNEL the Orb for a Spell Aim attack! Spell Aim is not a common build for the Monk but it's an interesting option.