Then you can cast the nonlands and then use your Treasures to cast them too
Seven mana for a 15/15 or 20/20 that your opponents wont want to kill is strong, and this card can go wide with a sacrifice outlet, too
I can see it winning the game if it sticks Zendikar Resurgent or draws 10 cards off Soul's Majesty, but the trouble is that those games would be few and far between because this is a bad, no-good deck
First, if someone says they're going to have Lutri be their companion, it's the easiest thing to fix: you just say, "Hey, did you know you can't do that?" and it likely changes what their deck is doing very little
Detective Pikachu has 18 cards in total
Commandeer There are many non-creature spells printed through Magic history that are either very powerful, like Nexus of Fate, or may represent immediate wins like Emergent Ultimatum or, god-forbid, Omniscience