Just curious noob asking skill gem question

[AverageTrackedVehicleEnjoyer]

Will Firestorm + Concentrated Effect + Increased Area of Effect work?
And what will happen if i link Concentrated effect to Clarity? More mana regeneration?

[Svastik]

Concentrated Effect and Increased Area are opposite effects. They won't work together, but one or the other can be linked with Firestorm. They won't work with Clarity though.

[Shajirr]

Yes, they will work together. Increased AoE will cancel out the penalty from Concentrated effect.

Don't listen to Svastik.

Increased AoE will work with Clarity, increasing its range, Conc Effect either will not work at all, or will just reduce the range. If you read the skill description again, you will notice that conc effect increases damage - Clarity deals no damage.