I have never played against an optimized list but I know from experience that marath can go infinite in a number of different ways with cards like Mana Echoes Ashnod's Altar and Cathars' Crusade and then use Purphoros, God of the Forge to kill the board with infinite tokens. Marath is somewhat of an aggro general, but he recovers from board wipes so easily that he can swing for a ridiculous amount of damage the next turn. He also has way more utility than the generals that were just demoted to tier 3.

Marath has been described to me as a slightly worse Ghave, which is still a pretty good card. He (she?) is flexible enough that I could see a number of decent decks built around him/her.

Anyway....

Tier 1 Decklists:

Animar, Soul of Elements devoted combo by cobblepott. Link

Arcum Dagsson combo-stax by NarejED. Link

Azami, Lady of Scrolls combo-control. Decklist needed.

Brago, King Eternal stax by NarejED. Link

Damia, Sage of Stone control by Epochalyptik. Link

Derevi, Empyrial Tactician stax by NarejED. Link

Edric, Spymaster of Trest control. Decklist needed.

Jeleva, Nephalia's Scourge combo/storm by Moxnix. Link

Karador, Ghost Chieftain midrange/reanimator by cobblepott. Link

Narset, Enlightened Master combo by NarejED. Link

Prossh, Skyraider of Kher combo by NarejED. Link

Scion of the Ur-Dragon combo. Decklist needed.

Sharuum the Hegemon midrange by Gersttt. Link (needs a more direct link)

Tasigur, the Golden Fang control by ShaperSavant. Link

Teferi, Temporal Archmage stax by NarejED. Link

The Mimeoplasm reanimator/midrange by NarejED. Link

Zur the Enchanter combo by Skuloth. Link

Note that decks with my name on them are mainly placeholders and will hopefully be replaced by other fully optimized decks with primers down the road.

Sharuum: http://tappedout.net/mtg-decks/kitty-clan-ironworks/

Arcum: http://www.mtgsalvation.com/forums/the-game/commander-edh/multiplayer-commander-decklists/217163-arcum-dagsson-tinker-to-victory-1-30-2016

Brago: http://tappedout.net/mtg-decks/brago-lockdown/

Prossh: http://tappedout.net/mtg-decks/14-12-15-food-chain-prossh/

Glix's Empyre deck can be used as a placeholder, but it's out of date. It's good for a general idea of how the deck works. Same goes for Teferi. http://deckstats.net/decks/29321/338155-teferi-update-11-10-15/de. http://tappedout.net/mtg-decks/empyre/

I would have used Glix's Derevi deck for its great card breakdown, but it's way out of date and significantly weaker than my build. That's more or less the case with all of my linked decks; they're stronger than any other list I've found, especially Arcum, Brago, and Mimeoplasm.

On to Tier 2.

Alesha, Who Smiles at Death stax by angelforge. http://tappedout.net/mtg-decks/alesha-stax-1/

Captain Sisay toolbox/stax by NarejED (not a placeholder). http://tappedout.net/mtg-decks/sisay-mana-denial/

Daretti, Scrap Savant stax by Paramount. https://www.facebook.com/TopCommanders/photos/a.339060309516811.79093.304415172981325/740844926005012/

Gaddock Teeg Hate Bears/stax. Deck needed.

Ghave, Guru of Spores combo by vault. http://tappedout.net/mtg-decks/ghave-that-bitch-a-combo/

Grand Arbiter Augustin IV stax by BigLupu. http://tappedout.net/mtg-decks/grand-arbeater-augustin-iv/

Grenzo, Dungeon Warden combo by LandDestruction.com. http://landdestruction.com/grenzo-doomsday/

Jace, Vryn's Prodigy  ^Flip storm/combo by LandDestruction.com. http://landdestruction.com/jace-vryns-prodigy-edh-primer/

Jarad, Golgari Lich Lord reanimator/midrange by Razzlox. http://www.mtgsalvation.com/forums/the-game/commander-edh/multiplayer-commander-decklists/578765-jarad-graveyard-midrange-creatures-are-just-dying

Kaalia of the Vast stax by NarejED (not a placeholder). http://tappedout.net/mtg-decks/ill-kaalia-back-later/

Marchesa, the Black Rose midrange by NarejED. http://tappedout.net/mtg-decks/a-game-of-marchess/

Meren of Clan Nel Toth reanimator/midrange by NarejED (not a placeholder). http://tappedout.net/mtg-decks/lemon-meren-pie/

Mizzix of the Izmagnus storm/combo by NarejED. http://tappedout.net/mtg-decks/mizzix-spellslinger-test/

Momir Vig, Simic Visionary toolbox/combo by Jebus4054 (slightly outdated). http://www.mtgsalvation.com/forums/the-game/commander-edh/multiplayer-commander-decklists/582034-momir-vig-simic-toolbox-combo

Niv-Mizzet, the Firemind combo by NarejED. http://tappedout.net/mtg-decks/fo-rizzle-mah-mizzle/

Oloro, Ageless Ascetic combo/control by Ender666666 (placeholder. Need a more optimized list). http://tappedout.net/mtg-decks/sorrynotsorry/

Roon of the Hidden Realm stax by NarejED. http://tappedout.net/mtg-decks/prison-can-roon-your-life/

Saffi Eriksdotter combo/midrange by enpc. http://tappedout.net/mtg-decks/just-stay-dead-1/

Sedris, the Traitor King reanimator/midrange by NarejED. http://tappedout.net/mtg-decks/now-watch-me-whip-now-watch-me-trai-trai/

Selvala, Explorer Returned stax by Rienuaa. http://tappedout.net/mtg-decks/selvala-combostax/

Sidisi, Brood Tyrant reanimator/midrange by Voidia. http://tappedout.net/mtg-decks/sbt-combo/

Sidisi, Undead Vizier combo by Razzlox. http://www.mtgsalvation.com/forums/the-game/commander-edh/multiplayer-commander-decklists/650850-sidisi-ant

Sydri, Galvanic Genius midrange by NarejED. http://tappedout.net/mtg-decks/sydri-test-4/

Teneb, the Harvester reanimator/midrange by NarejED. http://tappedout.net/mtg-decks/teneb-test/

The Gitrog Monster midrange by r/CompetitiveEDH. http://tappedout.net/mtg-decks/cedh-brew-1-hypnotoad-the-gitgud-frog/ (upgraded list: http://tappedout.net/mtg-decks/feel-the-ground-croak/)

Yisan, the Wanderer Bard toolbox/midrange by LandDestruction.com. http://landdestruction.com/yisan-the-wanderer-bard-edh-deck/

What a mess.

Gonna update it later. Thanks a lot for the effort!!!