So, if the attacking creature's strength overpowers the defending creature's toughness, and the defending creature's strength overpowers the attacking creature's toughness, both creatures die
Glory (S, Block) While not as efficient as the most played Incarnation (Wonder), this Judgment creature comes in a close second
Its not exactly simple to do that, but its a nice goal to aim for
printing at normal card sizes means you can use normal card sleeves, which is nice (a non issue here, but something to think about when making your own stuff) and a d&d specific thing, a few spells need like 3 pages to fit the full text, even without a picture, so if you want cards that fit together, cards without images should probably be possible (i dont know the card generator, so it might be a non-issue here too)
Two cards have effects that require your creature to survive, but dont use the word win in their text
In addition to Peter, another low cost, high power card is Kit Cloudkicker Tough Guy (shown below in its promo form)