What you were looking for was Carth the Lion

Both the creative concept of "loyalty" and the mechanical concept of "more counters, less 'sacrifice'" seem an odd fit for black.

This definitely should use a wording that explains how to resolves players tied for highest life total.

Was going to say this name was taken, but then I looked it up and it's Liquid Fire. Hm.

Setting that aside, I'm pretty sure you can get more value out of your Reflexes with downside. I know it's supposed to be a way to exile opponents creatures, but that's still a corner case, two step process. The obvious choice is to just give the creature +1/+0. Though, given the flavor you're going for, maybe it would be more fun if instead of first strike, the card said "Creatures blocking or blocked by enchanted creature have first strike." Still a bad card, but harder to evaluate. ;)

Magictober 2nd: Potion

Magic potions are a staple of computer-game fantasy; but if we'r to go uncontrolled I think I want to go elsewhere for inspiration. Mythology doesn't actually have many - elixir of life, sleeping drink (which is probably just mead, let's be honest) and the occasional love potion (ditto). Other stuff that maybe counts would be medea's cauldron? Thor's goat-ressurrecting cauldron... there's a few of those, but it's not really a bottled drink.

Which makes me now wonder where the modern idea of a potion came from, actually. Probably snake-oil salesmen, to be honest.

So let's go there - mtg snakes are all about deathtouch and first strike. (Distinct lack of constrictors.) And there's an obvious way to combine that in a 'power but...' kind of way. You get one, your opponents get the other.

I kind of want to use "Other creatures deal damage to ~ in the form of deathtouch." to make the tie-in even clearer.

And now we have a problem - because "Enchanted creature has first strike" is firmly . Yet snakes are pretty much .

There is ONE solitary red snake. Fire Snake. So now we're applying a potion of liquid fire. ... I am surprisingly OK with this. Was "Ophidian Tincture".

Huh. Thallid Pit Fighter suggests a challenge to have a go at.

So "Fungus", and I'll try to give this sets initial theme a go. Which was something like "Power you can't quite constrain right".

A fungus the is slightly out of control? That feels like a very reasonable thing.

So an obvious thing is exponential growth, costing you some resource. Life is obvious, but I think I'd rather play to theme a bit more and have it eat stuff. I tried non-fungus creatures but that's just too easy to avoid any downside. But your graveyard gives you a nice bit of a buffer to get it going.

And if we're eating that - then eating your hand too seems like a way to make this into a kind-of-epic. And also gives some nice ways around it if you decide to stop - madness, things you can cast from graveyard, etc.

Still, dropping this as soon as you can is a somewhat bold move.

­R&D's Secret Lair says ignore all card-level errata. It doesn't revert the game rules

­Yurlok explicitly brings back mana burn, but yeah, loss of life not damage

Uh... R&D secret lab I think? The un card that says cards work the way they worked when they were printed. You can use that to bring back a card that cares about mana burn to bring the mana burn rule back into play :)

And.. yeah, I didn't know it was life loss not damage. So I guess that wouldn't work. And it wasn't even a rule in the unlimited rule book, so I can't check :)

What's that specific card? It used to be mana burn causes life loss rather than damage, so protection still would not be of use.

If it's a black defense against a white mechanic - or at least a reparation -, it should come with a black pay-off.