The Dash ability here really makes the card better than mediocre and into good territory
Collector booster contents vary wildly between sets, so heres what you can expect from a Final Fantasy collector booster as an example: 3 foil commons 3 foil uncommons 1 foil basic land 1 non-foil showcase art uncommon 1 foil showcase art common or uncommon 3 non-foil rares or mythic rares with Booster Fun 1 card from the Through the Ages bonus sheet 1 foil rare or mythic rare that could be a colorful chocobo or a serialized gold chocobo
Prosper, Tome-Bound Treasure and card-draw Tiefling warlock Prosper, Tome-Bound is a four-mana black and red 1/4 with Deathtouch that does a lot all on its own, but none of that is really combat-based
The color of the split cards is equal to the color of both halves as if they were one single card
Additionally, it went infinite with practically everything, a la Devoted Druid
This is one of the most common creatures to be cheated into play through reanimation effects or other shenanigans such as Indomitable Creativity
