Mindblade Spectre
These Mindblade Spectres will interrupt your spells, even spells like Death's Charge or Dwarven Stability that only have 1/4 second cast time.
They use the interrupt skill "Leech Signet", it will interrupt even if you have Shadow Form or Obsidian Flesh already up because these two spells do not effect signets.
You are still able to cast off of them following certain procedures due to the fact that they break at +33% Movement Speed. See Aggro for more details about breaking with movement speed.
Basically you want to gain distance between you and the Mindblade Spectres so you are out of spellcasting range. To do this, run forward with +33% Movement Speed to somewhat break their aggro and gain distance, and then also Heart of Shadow off of something to gain even more distance so you are out of their spellcasting range. Then immediately cast a spell such as Shadow Form. Be careful not to actually break their aggro if you need to keep their aggro.
See https://youtu.be/HIKR2o4D8xU?t=791 for an example of casting against Mindblade Spectres.
See https://youtu.be/xYVDivYgn8w?t=190 for an example of casting against Mindblade Spectres.
See https://youtu.be/xYVDivYgn8w?t=444 for an example of casting against Mindblade Spectres.
