For hosted custom games, it’d be fun to let loose some silly rules, akin to the Left 4 Dead mutations, like allowing duplicate heroes, or have every Pact-sworn spawn be a troll/flamerat
Maybe even in terms of more advanced mechanics like a slider multiplying the health of pactsworn or number of ambient/horde enemies
Of course it’d be important that a person can opt out of joining hosted games with custom rules with a simple tick (or they can be restricted to only private games)