Note that you need corpse explosion, not mass corpse explosion. I was wondering the entire time why the latter didn't work before I realize that there's a single target version of the spell.

where is the book?

just combine any piro and necro books

If you want to close out this quest you can find her in the graveyard east of where you fought the necromancer dog.

If you want to converse with the npc don't say you like the black ring....

Combine Pyro and necromancer book, deliver the book, to close the quest go to X:564 Y:128 its in the stonegarden graveyard

If you choose Black Ring, she will fight you. Killing her will net:
~15k XP
High Quality Tormented Soul
An Mey Falin (unique belt) 70 phys armor +2 Constitution, +1 Wits, 20% Poison resist, +1 Warfare, +1 Single-handed, +1 Polymorph
Robe of Power (epic chest armor) +1 Constitution, +10% Earth resist, +1 Scoundrel, 1 rune slot
Hjerna (Legendary Helmet) +1 Intelligence, +1 Huntsman, +2 Scoundrel, +1 Aerotheurge
Skin Graft skillbook
Door to Eternity skillbook

to be clear: combien ANY necromancer and ANY pyro book.

Where is the Necromancer Dog ? or how do i see Cordinates?