Morde - Yorick ult bug.
Okay, so when Yorick ults regardless of if he ults before morde ults or during, yoricks ult dies when morde ult finishes for what seems no reason.
Not casting it during Mordes ult but now since the new patch even if it's cast before morde ults regardless of anything else the maiden dies for what seems no reason.
Step 1. Yorick ults. Step 2. Morde ults yorick. Step 3. The ult ends, maiden randomly dies.
This happened 6 times during the game once morde realized he could abuse this, link above. (Skip to 40s to show the bug) this wasn't happening pre-patch, pre-patch the ult would stay in the normal realm and randomly attack things and still be alive once morde ults ends.
The video also shows morde ability doing 0 dmg while in ult.