Defending player's creatures get +1/+1? So you're meant to put this on the opponent's creature to deter them from attacking with it? But that's so much worse than Pacifism... Or if you're meant to use this on your own creature, as an Avalanche Tusker / Crashing Boars, it'll almost certainly mean suiciding your attacker while declaring no other attackers, because otherwise the pump allows your opponent a much wider range of beneficial blocking choices.

Is this meant to pump your own creatures? That seems reasonable on an Aura. Jelenn Sphinx and Soltari Champion did it for one card rather than two, so I think a conditional Glorious Anthem with the usual Aura risk of card-disadvantage seems fine.

Fixed.