Let's say Do-It-Yourself Seraph has the text boxes of both Beast of Burden (power and toughness equal to the number of creatures on the battlefield) and Psychosis Crawler (power and toughness equal to the number of cards in your hand)
Swing and land with one of your demon tokens
But I also think DIY boxes run too many risks of not meeting enough of the criteria I need when considering a deck box
If youre trying to rebuild your combo lines after a board wipe that Marwyn, the Nurturer wont mind this effect either
Together with Animation Module and then either Phyrexian Altar or Ashnods Altar, you can have yourself infinite +1/+1s counters put onto Feral Ghoul, which whenever you decide to stop, can then be transitioned into an-amount-of-your-determination Radiation counters onto your opponents, causing them to all effectively lose the game on their upkeep to both mill and life loss
Instead, you can have many fairies to take advantage of the increase