Force of Will becomes Force of Negation, and a few other changes to the payoffs would likely result in a monstrosity that focuses on cheating Omniscience onto the battlefield to get the cast trigger from Emrakul, the Aeons Torn
If that sounds daunting, don't worry
And yeah, your 10s will almost certainly still have flaws
You can play explore cards that let you hit your land drops more efficiently, it helps to play 3+ colors or expensive spells, it sets your graveyard for shenanigans, and much more
In a roundabout way, the very first FINAL FANTASY card I designed at Wizards ended up making it to print
I tend to use Mental Misstep for late-game counter wars where it counters things like the elemental blasts, Veil of Summer, Dispel, Silence, and the like