Saddle 1 Whenever Calamity attacks while saddled, choose a nonlegendary creature that saddled it this turn and create a tapped and attacking token that's a copy of it
All the other Arena-exclusive cards could very well have cardboard counterparts if Wizards wanted, which makes them pretty inconsequential to the discussion
Manifesting a card puts it onto the battlefield as a 2/2 creature, and you can turn it face-up by paying its mana cost
Lowering a creature's power Blue is the color that gets N/-0 effects, what R&D nicknames "shrinking." This can be done on an instant, often affecting more than one creature until end of turn
Long, tense, back-and-forth games of Magic are great, but in this format they felt forced
Some cards are designed for Constructed and cause problems in Limited