Actual Burn (see description)

I recently tried MTG and had a lot of fun playing burn decks (Mono Red and Rakdos). This deck is the closest I could get to pure burn in Eternal.
Gauntlet Only
It seems Eternal developers don't want pure burn to be a powerful strategy on ladder (for a good reason; It's the most frustrating strategy to play against).Red does't have any good card draw (Cauldron Cookbook doesn't count. It's too slow) and Tempo is a much more viable strategy for aggression. I don't recommend you to play this deck on ladder. If you run into Vara, you lose almost every time.
You can run this on ladder and get some wins here and there but the results won't be consistent. Just try it in Gauntlet and have some fun if you are a degenerate burn player like I am. It's pretty cheap anyway.
In terms of results, the deck performs well in gauntlet (it's not the best by any means but can pull off good results consistently). Final Bosses are hit or miss though. Most of the rules don't benefit your deck but you can cheat your way to victory about half the time.
Main Strategy
You aren't looking for any creature damage in this deck. Some early chip damage is always nice but not necessary. All the creatures are for chump-blocking and sacrificing. Most of the time, you need to hold power for chump block into sacrifice in your opponent's turn. You almost never want to play your sacrifice spells during your own turn. Almost all your spells help you to chip away some health and set up lethal.
Card Choices
Harbinger's Bite: Best card in this deck. Nightfall is a wonderful mechanic for burn. (I think that's why red doesn't have Nightfall). This card practically reads "your opponent takes 3 damage and you gain 1 life, both players draw a card". You almost don't care about your opponent's hand. Hand size doesn't matter when they're dead.
Torch: No brainer. Disgusting broken card. every deck with red should run this card. Great at doing every thing this deck is trying to do.
I would run 25 copies of Harbinger's Bite and 25 copies of Torch if I could.
Kaleb's Favor: Chip damage+ fire sigil. Having extra max power is helpfull for casting multiple burn spells in a turn or playing a unit and having enough power to sacrifice it. I'm not sure about the number of copies.
Devour: Efficient card draw. Eternal lacks efficient card draw in general (other than blue). This card is an exception. The healing is also nice because you are constantly racing your opponent with this deck.
Piercing Shot: Great answer for early game creatures that also helps your main strategy by chipping away some health.
Execute: Great card for this deck. There is a bunch of life gain in the deck that allows you to get one hit from a big creature (or chump-block it) and kill it the next turn. Don't underestimate the 2 damage. Chip damage adds up pretty fast.
Extract: Damage, Life gain and scout all in one card. It's not efficient though. 3 power is a lot for only 3 damage. I couldn't find better options. It's not a centerpiece for the deck but it's still a good card.
Burn Out: BIG DAMAGE specially in conjunction with Ticking Grenadin.
Obliterate: EXTRA BIG DAMAGE. Wonderful card. can be used as removal in desperate times but usually goes face.
Using Burn Out at the end of your opponent's turn (remember it's a fast spell) into Obliterate during your next turn is 11 damage and usually results in lethal.
Creatures: As I said, nothing more than sacrifice targets. I'm not so sure about the combination. Dark Wisp might be too slow.
Cull the Deck: Digging up lethal in desperate times. Might replace it with Quarry cause it's faster. I'm not sure yet.

Thanks for reading. I hope you have fun with the deck. I also appreciate your comments if you have ideas on improving the deck or have any burn deck in mind.