While Adrien is more confident facing 20 wights with his spell arsenal as he can throw in solid fog (btw, forcing every mob move 5'ft per move action) and it covers 40'ft radius.<br/><br/>Black tentacles is 20'ft radius but it grapples everything what is in zone or tries cross it. Web spell is also good. Then there is his Haboob (http://dndtools.eu/spells/sandstorm--85/haboob--3133/) spell which does 4d4 dmg per round with no save in 20'ft radius and lasting 8 minutes. So if he throws black tentacles and then solid fog and then Haboob, it can kill all wights (assuming they do not have second exit or such from there).<br/><br/>But it asks coordination of other casters also as I doubt wights just sit to take all three spells at once and lots depend on initiative roll and do wights resist black tentacles.