What's the most challenging deck you know that is legal in a format on MTGA and has a reasonable winrate

[u/sad_panda91]

I feel like having a headache tonight so I was thinking of a bit of a challenge

I have heard many tales of decks like lantern control and maybe a couple others that are renowned for being extremely hard to pilot and where the skill gap between people familiar with the deck and unfamiliar with the deck is really large. It doesn't actually have to be a "deck to beat" in the format, but the winrate should be at least reasonable or close to competitive viability. If it's hard to win with it mostly because it's just really bad that kind of defeats the purpose. It should be a well optimized deck for what it's trying to do, it's just really convoluted and hard to pull off and/or there is a lot of very important micro optimizations.

in good hands the deck should be in the ~40-60% winrate ballpark or something, but I am ok with "kinda bad but otherwise fits the bill" decks. If the wins feel earned, it did its job.

Since I only play on arena nowadays, one such deck that is legal in an Arena-format would be great. Brawl and Alchemy aren't ideal but fine for the purposes of this.

Bonus points if a mere mortal like me looks at the deck list and goes "how does this even win?" and you don't spoil it for me :)

[u/Mrfish31]

Probably something like tainted pact as mentioned for Historic.

In Pioneer it's not particularly complex over all, but Cat-Oven decks take some sequencing skill to squeeze every drop of damage out you can from [[mayhem devil]], extra cat sacrifices, extra food generation, etc. and now more recently how you can go for a combo kill with [[ygra]] seemingly out of nowhere when you're dead on board. I know my win rate in a Jund Food mirror is quite a bit above 50% because I know the deck enough to pilot it better than (most of) my opponents.

[u/Mrfish31 → u/Mrfish31]

Wish you'd been playing before [[goblin Trapfinder]] got nerfed because there was a very strong but convoluted combo with [[ominous traveler]] and [[Ashnod's alter]] that, in the hands of a good pilot, was quite likely the single highest win rate deck Historic has ever seen. Mystmin, the guy who created or at least popularised it went 93-8 in Bo3 matches with that deck before it got popular.

[u/mtgcf → u/Mrfish31]

All cards
goblin Trapfinder - (G) (SF) (txt)
ominous traveler - (G) (SF) (txt)
Ashnod's alter - (G) (SF) (txt)

[u/mtgcf → u/Mrfish31]

mayhem devil - (G) (SF) (txt)
ygra - (G) (SF) (txt)

[u/horexio]

[[Tainted pact]] decks can be very good, but the win con takes so many clicks. Did it once, never again.

[u/mtgcf → u/horexio]

Tainted pact - (G) (SF) (txt)

[u/marlospigeons]

Ygra Combo (especially the golgari version) and Lotus Field Combo in Pioneer both have really high skill ceilings and are competitive.

[u/ShamblingKrenshar]

This is super specific to the matchup, but when Sultai Reanimator was a thing in Standard I absolutely loved playing the mirror. The best moment for me was responding to an opponent's Bring of the Last Gift trigger by playing a card that let me discard a Terror of the Peaks, which could then kill them via ETB triggers before their reanimated board could swing for lethal.

[u/Maple_Ceres]

So, it's not available on Arena but from a historical perspective, my judgment would go with Doomsday in Legacy.

The titular card [[Doomsday]] is so open-ended and you have to select your pile based on the interaction you suspect your opponent has access to in the correct order. Very hard deck to master, but imo it's even more complex than Lantern, and I play that deck in Modern.

Again, I know it's not really what your looking for but I think it's a cool shoutout.

[u/mtgcf → u/Maple_Ceres]

Doomsday - (G) (SF) (txt)

[u/elkingo777]

Lantern Control in Modern

First result for a quick google search - https://www.mtggoldfish.com/deck/7953231#paper

EDIT: Missed the arena bit of the post. My bad.