Molten Shell support gems questions.

I imagine increased duration modifies the ten second duration it has but would Life Leech cause the explosion to heal since life leech isn't restricted to physical damage?

Also, what other support gems work with it? AoE increased? +Fire Damage doesn't as that converts a % of physical to fire, and theres no physical involved.

If you have a lot of strenth, try iron will. It should boost your damage significantly.

Concentrated effect adds a lot of damage. Life leech should work and mana leech works to (tried the latter).

I'm a big fan of Molten Shell (with quality) + Chance to Ignite + Elemental Proliferation + Iron Will on strength casters and grabbing burn stuff (with or without Searing Touch/Cloak of Flames).

Your shield pops, the screen lights on fire, and everyone that tries to come into your fiery zone of death dies about as quickly. Repeat for the next screen.

Iron Will
Fire Penetration
Concentrated Effect
Increased AoE
Life Leech
Crit Chance
Crit Damage

Concentrated Effect does give a lot of damage, but without any other AoE modifies the blast becomes too small to hit big monsters like Bears without manuevering right on top of them.