Seven Kingdoms: Seowyn's Crossing
The Mindslayer was a Shardmind who served the will of the Far Realm. He attacked the Fire Wasps under a time of Aberrant Sky. Although he slew Kidalis Havengard with the power of his psychic lobotomy, he was slain in turn, and Brother Eustace was able to return Kidalis to life. If the Mindslayer will stay dead remains to be seen.