Unearth mini bombers

I’m trying to create mini bombers with unearth. Currently using infernal legion and minion instability. Looking for help finding other support gems to pair with these.

What would be some good support gems to pair with unearth (minion instability and infernal legion). Just looking to use them to run in and explode. Any skills that would increase the explosion damage, radius, or cause a chain effect? Or that would create more corpses? Running an arsonist build so main damage is from arsonist and raging spirits.

Thanks.