The goal of this deck is to abuse as as many of the "opponent gains life" mechanics as possible. These cards trade opponents life for low mana cost strong cards, but with Tainted Remedy make them completely overpowered. This deck has an aspect of burn, control, and midrange that call factor in.

Center Pieces

Obviously the most central card to this deck is Tainted Remedy. With it out, every life gain card becomes very cheap burn and every life tradeoff becomes extra burn as well. This biggest problem I saw with these decks before is that if you are unable to play Tainted Remedy within the first few rounds, the combo won't catch up in time. However, this can solved with Tree of Perdition. This card has been a real powerhouse in my playtests. Essentially, it turns every life gain effect in the first few rounds into extra toughness for our strongest blocker as well as locking them at 13 life when it's time for our final burn.

Burn

Once Tainted Remedy is in play, there are a wide number of burn options in to quickly win. Beacon of Immortality is a fantastic game ender. Doubling the opponents life is equivalent to gaining life equal to their current total, or with Tainted Remedy out, putting them at exactly 0.

Cards such as Heroes' Reunion and Congregate are very cheap ways to deal lots of damage very quickly or as a way to keep usalive until more powerful cards come out.

Tree of Perdition also will most likely win in two with Tainted Remedy on the board. The first time it taps, our opponent drops to 13 but the next time loses the difference, either killing them outright or making them easily defeated by any burn we have in hand.

Control

Devour Flesh Condemn and Blessed Alliance are cheap control methods with very little downside due to our center pieces, eventually working as small burn as well. I need to experiment on which cards work best here, but it should effectively keep some larger threats off our back until our wincons come through.

Midrange

There are two ways to win through creatures in this deck. The first is Kavu Predator . While Tainted Remedy will eventually neuter his usefulness, Kavu Predator can ramp up to absurdly high power with our life gain burn spells.

EDIT It may seem contradictory to give an opponent 7 life only to take 9 away, summing 2 damage but the threat of having a 9/9 with trample on the board turn three is undeniable. In addition, once tainted remedy is on the board, Kavu predator is essentially neutered so its very important to get it to a high level right away, or just chump it away if you need to buy a turn or two.

The second method is through Assault Formation. This card turns Wall of Shards into a powerful 8/8 flyer, that also gives a slow burn condition, or ramps Kavu Predator. More importantly though is its effect on Tree of Perdition, who turns all the life we gave to our opponents into the most deadly plant in the game.

Sideboard

The sideboard is mostly for fine tuning our burn/control to the opponents deck and finding ways to counter enchantment hate.

EDIT after much consideration, I've decided to give up on budgeting this deck and make it work. The sideboard is quite expensive just off of the Leyline of Sanctitys, but with it is necessary for any burn/discard control an opponent may have. Rest in Peace is a fantastic answer to any graveyard interaction that a ridiculous amounts of decks have. Congregate and Yahenni's Expertise are both solid answers to decks that go wide and Stony Silence is a precaution against affinity decks. Thank you @Neaan

Maybe board

EDIT After going through many of these, i think its safe to say that most of the additions just diluted from the cards I needed out. I've added a few more, but I doubt any apart from Kin-Tree Invocation will be of great use. The only match up, I am super unsure about is Tron, but I've never actually played against it, so any recommendations are welcome.

Budgeting

After adding an actual manabase and some staples into the sideboard, the cost of this deck jumped quite a bit. So for a quick breakdown:

Lands- $37.74

Creatures- $26.44

Enchantments- $5.71

Instants- $23.65

Sorceries- $34.14

Sideboard- $108.16

Therefore, the essence the deck (without lands, without the sideboard, and swapping Idyllic tutor for more of the actual enchantments) comes to $57.57. That won't win you a GP but is definitely cheap enough to play at your LGS, or whatever other cards you already have.