Optical Blast is a warlock observer skill. It is best described as a hybrid of Silence and Counterspell with an added small damage component. When used, it will silence its target for three seconds; if the target was in the process of casting a spell, however, then the spell will be interrupted and the target will be unable to cast a spell from the same school of magic for six seconds.
Optical Blast, like all of the minion skills, can be set to auto-cast; however, as the AI will normally use this skill to immediately silence its target, rather than attempt an arguably more beneficial interrupt, it might be more viable to disable this. Disabling auto-cast will allow the warlock to decide if a spell is worth interrupting, or if the target is enough of a threat to use an interrupt on.
Use of this skill will usually force an NPC caster to enter melee combat, where they are at a considerable disadvantage.
- Patch 5.0.4 (28 August 2012): Added.