In standard we have very funy combo deck. It is based on this cards:

Witch's Oven + Cauldron Familiar + Mayhem Devil

In this deck you are cooking cats in oven to generate food which allows you to reanimate this cats and btw. some devils spreading damage to targets you want. Pure evil...

Playing this gives a lot of fun, not for opponet of course. Let's look on the good list 1/470:
https://mtgdecks.net/Standard/rakdos...mernaut-957982

Is it playable in Legacy? Maybe it could be but form had to be little changed.
We could try to use good Hogaak list a a base (how much cards of type use, etc. and add cards from standard wisely in this template). As a template I will use this:
https://www.mtgtop8.com/event?e=24620&d=372214&f=LE (1/73 players).

So after merge we could construct list like this:

Lands:

4x Badlands
4x Bloodstained Mire
1x Blast Zone
2x Castle Locthwain
1x Maze of Ith
2x Polluted Delta
2x Mountain
3x Swamp

Artifacts:

4x Witch's Oven
0x Altar of Dementia (it has to be tested, but in this build I didn't find place for it).

Creatures:

4x Cauldron Familiar
3x Carrion Feeder
3x Gravecrawler
4x Bloodghast

0x Cabal Therapist - he is probably good here. But it's topic to discuss how much copies we should add and for what?

2x Priest of Forgotten Gods
2x Fiend Artisan

4x Kroxa, Titan of Death's Hunger
0x Hogaak, Arisen Necropolis

4x Mayhem Devil
2x Judith, the Scourge Diva

2x Rankle, Master of Pranks

Spells:

4x Faithless Looting
3x Cabal Therapy

Sideboard

3x Leyline of the Void
3x Pharika's Libation - Diabolic Edict ++
3x Angrath's Ramapge
3x Dreadbore
2x Thoughtseize
1x Cabal Therapy
0x Claim the Firstborn
0x Act of Treason

What do you think? How we could introduce new archetype into Legacy? :D