[Edi]

Yes, it is a magic weapon, and yes, Anthrax did hit his targets, he just caused no damage. I was sitting right next to Kaljamaha watching it happen, we were playing a hotseat co-op game at my place, and this phenomenon was systematic over several battles, summer lions and other fire immune units simply did not take any damage from the Banefire Strike, but they got zapped by the banefire shield.

Anthrax is the only unit armed with Banefire strike, and if banefire differs from normal fire attacks in ways other than having the additional decay effect, it is possibly bugged so that the game thinks his normal attack is fire when it should not be.

Edi