001 Spinarak
Both are viable, but not in the same match-up
Cards like Narset of the Ancient Way and Sorin, Grim Nemesis benefit from discarding a split card since it deals damage equal to the mana cost
The storyline ended without having a epilogue quests, thus unable to progress the optional quests such as the Card Battle at the very beginning
You can find all of the cards in the soft glow, Ninja, Samurai, Phyrexian, and borderless treatments in Set, Draft, and Collector Boosters, in both non-foil and traditional foil
Cards with effects that are too small or too expensive, for example, Hissing Miasma only makes opponents lose 1 life, Hedron-Field Purists costs 15 mana to prevent 2 damage from each creature, Orim's Prayer only gains you 1 life per attacking creature, etc