My Skeletal Lerper and Inkblight Witch was engaged to an opponent's Nightmare. But Skeletal Lerper's Flanking did not proc. I believe it is due to 1x1 and 2x2 engagement-interaction.
Flanking + Soulreave is bugged. My Skeletal Lerper did not deal an additional 5dmg. The sound effect for flanking was heard.