my turn - rogue hunter
chops (3 drop 3/4)
opp donna calister (5/drop 1/7) + anything else non elusive

chops - when chops attacks exhaust target hero or ally
donna - when an opposing hero or ally attacks ready donna callister

can i propose atk with chops on 2nd character and name donna to exhaust her before he can protect with her?

when chops attacks, both powers trigger. all your triggered powers are added to the chain (since you have priority), then all opponent's triggered powers (708.1a). so donna readies, then chops exhausts her. all of these trigger and resolve before the protect point, so donna would not be able to protect, she would be exhausted.

this issue has come up before with voss treebender.