This bug is very simple.

When Erleng Shen dies, my FPS will drop to ~60 FPS. It does not matter if it is an enemy or friendly Erleng Shen; his death will result in a massive FPS drop.

My graphics card is an AMD R9 Fury with the latest drivers, 16.6.2. I also have an Intel i5 6600k with 8GB of memory.