Shattered Obelisk Invasion

2017 event arc Shattered Obelisk Invasion included loot from mages similar to the Shadowlord Invasion spell books from 2008.

These are highly prized for the high Spell Damage Increase.

Invasion Spellbooks

Slayer Spellbook

(slayer type) Slayer	Random
Defense Chance Increase	10%
Spell Damage Increase	30%
Faster Cast Recovery	2
Lower Mana Cost	5%

Non-Slayer Spellbooks

Spell Damage Increase	50%
Mana Regeneration	3
Faster Casting	1
Lower Reagent Cost	10%