My dad and I had some truble the other day vs a golam in the crossroads that had extra health, health regen, extra damage, and damage reflection. I'm not sure which was a arua or not but it took use for ever to kill it. Infact we use all our flasks and my dad died once place plus we only took it down after running away to find bodys to raize as zombies to tank it as we blasted it, which still took lots of zombies. I don't know anything can or should be done to make sure overpowered combos don't happen.