Mental Misstep was banned in the initial Modern banned announcement, based mostly on how it played in Legacy, where it essentially pushed one-mana plays out of the format and made most decks 56 cards, since everyone had to run Mental Misstep, not so much because they wanted Mental Misstep in their deck but because they needed to be able to counter their opponent's Mental Missteps
Setessan Champion Setessan Champion is another constellation enchantress but is cheap and, most importantly, becomes a powerful threat in its own right
You can tap it with two to destroy an opposing nonbasic land, so it's land removal
As you can see, this format has all of the mana you need but just one spell cast per turn, so only copying one per turn won't be a restriction, and getting the copies for free each turn is big value
This Atarka is considered accessible enough to front the Draconic Destruction Starter Commander Deck