Update 1.10.5.1: The Swarm!

New Weapon Added: Cinderfall Sword, Venom Axeblade

Improvement: Revised the item damage modifier code for mobs such as
Geonachs (weak to pickaxes) and Spriggans (weak to axe). Any item that
is effective at mining a block similar to the mob such as stone for a
Geonach or wood for a Spriggan will now deal additional damage to the
mob. Before the code searched specifically for vanilla items or items
with pickaxe, axe, etc in their name which wasn't the best way of
implementing this.

Bug Fix: Inferno Mobs such as Cinder should never take any damage from
Fire damage types. While they were already immune to being set on fire,
damage that was treated as fire damage would still damage them.