You can buy Skill Books from vendors in SoD Phase 4

Wicked Warlock - warlock s book slot It was introduced as a non-core base class who practice arcane magic in the supplemental book Complete Arcane for the edition of Dungeons & Dragons In 4th warlocks book slot You can cast Bestow Curse with a warlock Spell Slot Warlock Level 5 Book of Ancient Secrets You can inscribe magical rituals in your Book of

warlock spell slot table The damage penalty of Shadow Bolt Volley has been reduced to 5% ; A New ability has been added to the game via a spell book: