Firecape added to range and mage::
People like to show off their achievements, why not make a variant where you can add a firecape style to your avas, or mage arena cape where your God symbol flows with lava. Each variant could have a +2 or +4 variant to range or mage damage.
While I support the general direction of your idea I think conflating it with the fight caves may not be appropriate lore wise to arbitrarily add in like that.
For example the Infernal cape
does
make sense in this aspect.
We should definitely do something like what you're saying though at the high level!