Minecraft version: 1.12.2
Wizardry version: 4.1.1
Environment: SMP
Forge: *.2702

In this instance im presuming a wizard died or a zombie or something and the msg said: death.attack.indirectWizardyMagic

Ok thanks for reporting, I'll get that fixed for the next patch.

Addendum to this, now its live on the server, this msg is spammed quite a bit

I can actually see a second issue there, it shouldn't print out a death message when a minion dies because that happens quite often, as can be seen here! I think it's doing that because the minions technically have custom names.