unlimited hand size cards mtg Amazon.com: Magic The Gathering - Enter The Infinite (34) Damage wears off o:no o:maximum o:hand · Scryfall

You're probably noticing a certain green theme of taking any given number and multiplying it by two

That is, until your competitor drops a ruthless and unexpected card to take an extra turn that leads to a game-winning play

The downside is that we can get wrecked by the targeted creature going away before resolution, countering the spell

Another important point why Atraxa is "only" rated as a high power commander, is because in her commander identity you have already the top partner pairing of TnT = Thrasios, Triton Hero + Tymna the Weaver

Arena of the Ancients does shut down legendary creatures, but the effect is symmetrical, so unless you specifically craft a deck that avoids them, it's going to impact you too