i once built a aethreos decki just filled it with tons and tons of wrathsjust get some gd enter or leave the battlefield/die effects, and may them pay the 3 lifeaethreos doges most wraths since its ID, careful not to use -1/-1 wraths such as black sun zeniththen put tons of recursion stuff in it, such as rise of the dark realmsthen u can go to town with the deck! keep wrathing and keep letting them pay life, so everyone will hate u <3 good luck

Thanks for your comment :) I added indeed Wrath of God and Rise of the Dark Realms, i think they'll both be good in here.

& life gain?!?!

Consider Divinity of Pride, Vampire Nighthawk, Gwyllion Hedge-Mage (hey why not?), Deathbringer Liege (for control and stronger creatures + he grantee Aethros's a creature), Serra Ascendant (pricey though), Rhox Faithmender you can't miss that one, he's massive in any lifegain decks. Also Archangel of Thune, another massive card in lifegain.

With Soul's Attendant (which you could replace with Soul Warden) and Suture Priest, you want more tokens and way to sacrifice them in order to make full use of their abilities. In that order of idea, Ophiomancer gives you a good chomp blocker at each of your turns, Thraben Doomsayer is usefull and recurent and Requiem Angel makes spirit out of any non-spirit, how's that? If you go farther down the roads to token, conider Blood Artist and Dictate of Erebos / Grave Pact or Martyr's Bond in white, which is better also.

Does infinite Exquisite Blood coupled with Sanguine Bond temp you?

In instant, consider more removal and some draw like Night's Whisper, Sign in Blood, Read the Bones, Doom Blade, Go for the Throat.

I do realise there is a few non-budget friendly cards in there, but if you choose one or 2 of 'em, I think you can still mange especialy through trades or with played cards.

I hope this helped! and if you want to take a look at other EDH decks, check out EDH Who's that guy? !

You could try taking a page out of the Soul Sisters deck:

Serra Ascendant - An absolute beast in EDH.

Martyr of Sands - Could potentially gain you a ton of life and make your opponent frustrated when you already have Athreos out.

Maybe Rhox Faithmender; and on that note, Exquisite Blood to combo with your Sanguine Bond. If not this deck, then where?

You should have Exsanguinate in there too, in addition to Debt to the Deathless, and maybe even Kokusho, the Evening Star (who is pretty dang awesome with Athreos.

Actually, after looking at your list, you should probably increase the number of creatures you're playing to maximize the usefulness of Athreos. Also, I think you're playing too many lands. While I agree that a deck should have just under 50% of it able to gain you mana in some way, I usually play a land count of between 36-40. The rest should ramp or gain you some additional benefits. After all, you need to have the mana for your win cons. You pretty much need Solemn Simulacrum in this deck. Burnished Hart is an all-star. Weathered Wayfarer is a big help against green. You can even play Walking Atlas to help you out there. It's pretty good when combined with Liliana of the Dark Realms.

You should probably capitalize more on the fact that you're gaining life. I also noticed a lack of card draw. A few cards that can help you out here are Bloodgift Demon, Graveborn Muse, Phyrexian Arena, and the big daddy Necropotence.

Killing Wave isn't really a good kill spell in EDH. It gives your opponent's the opportunity to keep that one thing that's about to kill you. I'd recommend Toxic Deluge in it's place.

Anyway, those are some of my thoughts. Hope they help.

Thanks @Joumba and @Somnambulist for your help ! Thanks to you my deck is taking shape.

I wish i could play Deathbringer Liege, Archangel of Thune and Kokusho, the Evening Star but they're way out of budget for me right now. I'll get them sooner or later though :)

There are some of the cards you suggested that i did not add in my deck at the time because i didnt have them yet, but i finally received them. I'm talking about Exquisite Blood, Rhox Faithmender and Exsanguinate in particular.

As Joumba suggested, i'll think i'll put a bit more tokens in it, because I like Teysa, Orzhov Scion and it can do some cool things. I won't put aside the main theme of black and white life gain/loss, i guess it'll be a sub-theme of the deck :P I really really like Ophiomancer, thanks for the suggestion.

Deck slowly taking shape, thanks again :) I'll add new cards as soon as i get them.

How about kill their creature then take it with Debt of Loyalty? Great way to take stuff after a non Wrath of God Sweeper.