Just want to point out that if the enemy QOP had a hex, all she has to do is blink in and hex you. Have fun trying to use your BKB as a chicken, while I laugh at you with my additional 1k health from heart. There's nothing wrong with going Heart on AM. In most cases it's better than BKB. AM wins fights often because the entire enemy team focuses him, but he ends up blinking out with 100 health while the rest of his team comes in to clean up. Then he just waits 10 seconds and jumps back into the fight with 1/2 to 3/4 health. BKB, on the other hand, assumes that you're the one initiating and not the other way round. The duration also gets pretty short late game (5 seconds is barely enough).