What the F happend to Blood Magic?

Problem:
March of the Legion is a very low-cost method to gain four extra auras on some builds due to the change where Mana is not being required in order to cast an aura. It also took full advantage of the Supreme Ego keystone in a way that goes against the intent of the mechanic and gained a significant amount of power in the process.

Solution:
Rework the Blessing mechanic of March of the Legion to limit the number of Blessings you can have to one. Change the skill to cost mana instead of temporarily reserving mana. The process of making this change also highlighted a number of problems with other mechanics which has led to a ripple effect of other changes being required. Release Blessing as a Support gem, to make the mechanic available to builds that are not using the unique item. This is intended to be useful for high mana-use characters who wish to leave their mana unreserved and for characters using the Blood Magic keystone. Improve the aura level granted by March of the Legion so the item excels at using a Blessing aura. Remove Mortal Conviction and the life passives from behind the Blood Magic keystone and make a Mortal Conviction-style support gem that makes an aura free, and prevents you reserving mana. It will be mutually exclusive with Blessing skills, so you won't be able to use both simultaneously. This support gem provides slightly less aura effect to the skill than the Blessing Support but has no cost or upkeep involved. Change Blood Magic to also grant 10% more life to compensate for the removal of the efficient life passives behind the keystone. Change Supreme Ego to not limit you to one aura and instead give more aura effect based on how much mana an aura reserves.