You can play many of the more heroic legendary spiders from the Spider-Man sets, and there are many other niche counter types you could double with Ultimate Spider-Man
You can figure out if your card is Enchanted not only from the rainbow hexagon symbol, but also from the artwork as Enchanted cards offer a full art piece, taking away the border and using colours in keeping with the artwork
Im not sure how much a Grixis deck cares about that, but lets include the corner cases since there arent many frogs to chat about
The criteria I asked people was to use when evaluating the cards was, How good is the card now and how good is it likely be in the future? I specifically told each person So, you dont need to give Morphling high marks for being awesome ten years ago. There were no set parameters on what constituted a ten or a one on the list rather, the subjects were asked to rate cards in relation to one another, and were largely left to their own devices to figure out how they wanted to score cards
Necropotence gives you a great devils bargain: dump in a bunch of life, draw 20-35 cards in your end step, and hope to untap so you can win the game
Survival abilities (and other abilities that trigger at the beginning of your second main phase) will trigger at the beginning of the second main phase you take in a turn