[1.7.4 Cults + Embers] Infinite XP using AAD + Light of Revelation

[Erenion]

The Light of Revelation has a 4% chance on dealing damage to a foe of normal rank or lower to transform that foe into a horror.
Said horror is worth XP.
Using the Arcane Amplification Drone, which counts as hostile, you can summon an infinite amount of horrors that you can kill for experience.