mtg steal opponents cards commander Theft commander that locks you out from playing your own cards once he is on the field. : r/custommagic Sen Triplets Steal Theft Copy

If you are willing to pay for the service, Beckett has been an industry standard for trading card valuation (well beyond just MTG) for generations

I run this all over the block in places like Abe's Deck of Happiness and Joy

The big downside is that this white creature is extremely hard to cast

In other words, either the creature remains untapped when the convoke card goes on the stack, or the creature is tapped to pay for the card as it goes on the stack

One more before you go, Salvation Engine not only reanimates an artifact, but it pumps up any army of artifact creatures with a solid buff just like Tempered Steel

It doesnt allow you to skip paying the mandatory additional costs and it doesnt forbid you to pay for any optional ones (such as Kicker)