A Dark Messanger spawned within range of my Grintmaw Bouncer, an attack was made but the bird lost damage from the original 40 HP to 30 HP, then had it's HP to 10 HP. So pretty much Defensive Strike should've killed Dark Messanger, but it didn't.
Thanks. This is another manifestation of the problem where using existing champions and modifying them on deploy creates a problem. Either way, Raven Tongue was already slated to get its own version of the rune to summon specifically, so that'll address this also.