How to build fire ball - chain or pierce?

Is there a way to make fireball a powerful map clear whilst still maintaining good single target vs end game bosses?

The way the skill is coded, the explosions will only occur at the end of the projectile if it pierces so 100% pierce + frostwall sucks where as chain is too expensive.

help!

Only way to make fireball good single-target is to focus on AoE damage, or ignite.

Proliferation has been buffed in 2.3.0 so that should be an OK choice.

For AoE, you can use conc effect to boost the single-target, or, use that threshold jewel and overlap AoEs to shotgun stuff.

For map clear skip both, go for scaling the AOE and then decide if you'd prefer LMP or GMP. With the good aoe nodes and the inc AOE gem, it gets pretty significant. If you don't care for that option or are an insane clear speed addict, remember that Fork exists, it is a thing.

With a little disclaimer that I haven't used fireball in a long time, I would go with an elementalist, use lmp or gmp and get the AoE nodes near templar and witch among others and use frost wall to shotgun fat single targets.

two rolling flames jewels
lmp
ele prolif OR elementalist
scale burn

flame surge for single target