Why does tear stack faster than Manamune?
So the upgrade to Archangel makes you lose the +1 mana every 8 seconds but you gain double stacking from spells. With Manamune, you gain mana gain on auto's and again lose the +1 mana every 8 seconds. Problem with that is that if you were already getting max stacks (keeping it constantly off cd) you actually just lost stacking power by upgrading...