Conjurer class help?

[Kitya]

Virus might not be the best skill to cross class. But it is useful against enemies who use physical damage. Because it lowers their strength and dexterity when virus is active. So they deal less damage

Virus is certainly a usable ability but not one that I've found the need for just yet. Of course, since we can transfer five spells and two of the seven spells we can transfer are 100% useless (ruin and physick) there's no point in not getting it.