Looking for a "phun" deck to try on Arena? Look no "phurther" than this "phour-color" Phyrexians pile (I'll stop with the "ph" jokes now.)
I love Phyrexians, but I don't particularly love a lot of the mechanics that come with them. Toxic? No thank you. Incubate? Eh, it's alright. But I found that most of my "phavorite" (sorry, last one, I swear) Phyrexians eschewed those mechanics. Instead, they were just really strong cards on their own. Glissa Sunslayer, Phyrexian Obliterator, Atraxa, Grand Unifier -- any deck would love to have these cards. So why not put them all in one deck?
That's essentially what this is: A very creature-based Phyrexian tribal deck. Despite being four-color (though the only blue comes from Atraxa, so this is more accurately an Abzan deck) with lands like Cavern of Souls, Secluded Courtyard and The Seedcore, plus Armored Scrapgorger as a Phyrexian mana dork, our mana base is really flexible (though we do lean a little heavier on swamps to have a better shot at casting a Phyrexian Obliterator or our handful of black removal spells.)
To keep our Phyrexians on top, we run four copies of Grafted Butcher for a cheap anthem and three copies of Phyrexian Censor to slow down our opponents.
Skrelv, Defector Mite provides a bit of protection for our most important critters, Gix, Yawgmoth Praetor gives us a few extra cards and Sheoldred, the Apocalypse, well...you know what she does.
You're still going to struggle against sweepers and more controlling matchups, and being so creature-heavy often keeps you playing at sorcery speed, but by turn 3, you should be able to throw out bomb after bomb every turn, oftentimes just overwhelming the opponent with higher quality cards.