What does "Arcane resource burn" mean?

[Shiroe]

And how it works?

[ghostbuster]

Arcane resource burn reduces mana and other magical resources (vim, positive and negative), and deals arcane damage.
Hence, 100 arcane resource burn will try to reduce mana by 100, vim by 50 and pos or neg by 25.
If some resource are reduced, arcane damage damage is dealt for the max of mana removed, or 2*vim removed, or neg or pos*4.

It is very useful against magical NPCs.
But completely useless against non magical characters (or if their arcane resources are already completely depleted).