I'm slightly intrigued by this card too but the small body and the one-time-use of its ability worries me. Dauntless Bodyguard is good because it's a good attacker that can save another creature from any death including a wrath effect. This Rescuer is not wrath protection and it can't protect anything the turn it comes down. If it attacked well I would test but that 2/2 body I fear is just too lackluster.
Let us know how your testing goes, it is a very unique ability.
Let us know how your testing goes, it is a very unique ability.