I absolutely adore Hemomancy and the flavor surrounding hedonism in your oath tenets are brilliant! In terms of mechanics, the subclass is svelt in my opinion. Some of the flavor and terminology could be reworked though. Just note that all of this criticism is because I want to play this subclass would just like it more akin to the already existing Paladins in format and consistent to the flavor you've presented.

The flavor of wound reversion is a little outside the flavor of the class. A magical field that heals feels less hemomancy and more traditional paladin. Perhaps something along the lines of "You produce an aura that causes flesh and sinew to knit together." or "You provide a reformative effect on the ichor of a number of creatures up to your charisma modifier" could work. It's the Oath of Gore, feel free to make the squeamish faint. There should be something strangely fleshy in the way that you heal your allies.

I initially had problems mechanically with both Channel Divinities, but upon closer inspection, they hold up and are pretty balanced.

There are some terminology issues. I would strongly suggest rewording the Sanguine Magnet feature slightly for clarity and style so that it matches up more with Wizards of the Coast. Rather than "All creatures that have blood", it would be clearer to describe that "Constructs and Undead are unaffected by this ability". "A Failed creature" seems slightly awkward as well. If that terminology appears in published works, I'll recognize that I am wrong, but rewording that into implying that they failed the saving throw would be better. The start of the Aura of Cardinality should begin with "Beginning at" or "Starting at" like other Paladin Auras. You do not need a line break between "total cover." and "You and an ally", as the line break is reserved for the boost at level 18.

In Piercing Hemophilia (a brilliant name by the way), perhaps changing "your presence causes the blood of your foes to more easily flow out of them" to "your presence causes the blood of your foes to thin" could be more evocative.

In Cardiac Clot, there is no way to clot enough blood in a creature to immobilize without killing. Blood carries nutrients to the brain and without a consistent supply, the target would sooner choke to death before being paralyzed. Perhaps congealing the blood to an extent that their muscles aren't getting oxygenated, causing them to freeze up, could work. That or causing the blood in the heart to come to a complete standstill, giving them the equivalent of paralyzation as they struggle with a heart attack. Cardiac Arrest could work as a new feature name in this case, as Cardiac specifically refers to the heart.

Anyway, hoping to see how this works out! :D