Easiest way to kill the final boss of the game probably.
Final Boss Guide
In the final boss room there will be 2 ball shape enemies and then the boss with his hands and head sticking through the window at the back of the room. The Cheese Location is to stand right up against his left hand (Your right) right in the opening of it. Right between his thumb and index finger. if you stand right here, both of the ball shape enemies in the room will bug out. The red ball will still fire lines of fire but they will slightly miss every time and for the spike ball, he will just sit there and not do anything.
Now you can still take damage from the main boss but here’s where your build comes in. You need to stack all of your skill points into as much life steal as possible. The easiest way I found is to go berserk slash as your main skill tree and stack any shards you have that will give bloodthirst back instantly (i.e. corrupted grasp, frigid bloodburst) as well as fully into any skills or shards that increase damage (lifesteal means higher damage=higher healing) and obviously any skills that increase healing. Here is the build that I used to out heal the main bosses damage. If you use this build and spam bloodburst and use bloodslash whenever its charged and rinse and repeat for each phase, it will be the easiest boss of all time.