Nice, I've been wanting to see other people's take on an Atraxa superfriends EDH deck. Right now I have a Cromat superfriends list I've had in the works for ages, been debating on whether it's worth losing the likes of Dack Fayden, Sarkhan Unbroken and the Bolases (especially God-Pharaoh who looks awesome!) in order to be able to run Atraxa as my general.
How does Nissa, Steward of Elements work out in the deck? Since your deck only runs 3 creatures, it seems like her 0 will wiff a lot of the time and while her other abilities aren't bad, they don't seem that amazing to me in Commander, but I could be wrong! I guess her second ability can be good for ramp, but it just seems so hit or miss to me, I feel like I'd rather just run a Kodama's Reach or something in place of her.
I see a lot of these decks running Nissa, Vital Force but she also never looked very impressive to me. Is it because she can recur Planeswalkers? Or is it because she makes a decent-sized chumpblocker (at the potential cost of a land)? If I convert my deck I'll need to replace some walkers so I might consider her.
What about Oath of Ajani and Gideon? Are they worth the deck slots, in your experience? I didn't try them in my deck because I felt like I'd rather have a mana ramp spell or another removal spell in their place. Gideon's does make a couple of chump blockers at least. Ajani's is like a pseudo mana-rock but I can't decide if that's worth it over just running, say, a Fellwar Stone or something. The +1/+1 counter ability of it seems mostly irrelevant to me, but of course in the right circumstance it can be pretty good.
How about Vraska? I had her in my deck but I cut her. 5 Mana for a pseudo-Vindicate just didn't seem worth it to me, and I've never liked her + ability.