Hello, I am level 80, but I consider myself a beginner. Indeed, I have been playing for several years in a relaxed way. I'm just doing the main story. I have a few questions about this job.

1- First of all, I regularly see rotations that start with ice magic. In my head, ice magic is good for gaining mana. Since at the start of a rotation I still haven't used any mana, why start a rotation with ice?

2- I don't understand the Umbral soul spell at all. (level 76) I may well reread the spell, but I don't see the point. Can someone explain it to me?

3- Some spells use all mana. I imagine the goal when using one of these spells is to use manafont afterwards?

4- Fire IV has 300 firepower. Despair has 340 firepower, but it uses all mana. Is it really a benefit to use Despair for 40 more?

thanks all