Nymphomanius wrote:If a small squad of assault Marines, striking scorpion, Genestealer pop up just 5 could quite possibly drop 10 firewarrior and 5 Pathfinder but if you can kill 1/2 with shooting Aun'Shi could finish what was left surely?
If you're sure that your enemy will try to deep strike close to your gunline, then Aun'shi would definitely help. If 10 Fire Warriors and 5 Pathfinders are charged by 5 Assault Marines, you'll get 30 shots in Overwatch, which comes out out to about one kill. As long as Aun'shi is performing a Heroic Intervention or otherwise hitting first, he can take down one or two Assault Marine every turn (5 attacks > 4.17 hits > 2.78 wounds > 1.85 kills).
However, I feel like your opponent could just avoid Aun'shi. Chances are they'll use a deep strike force larger than five models (if deep strike is part of their strategy), or even if they don't they could just drop their unit in a position where Aun'shi wouldn't be able to help in time.