While other cards might be a bit more fancy and powerful, Mickey Mouse, True Friend lives up to its name with a very dependable, solid card thats good at a bit of everything, for a very fair price
Like most Magic: The Gathering cards, the value of Regeneration depends on a few consistent factors: its rarity, the printing and finish (regular or foil), its physical condition, and the set it was printed in (Ice Age)
Grisly Salvage is the most potent of those on offer but I would start with Tracker's Instincts as you can use it from the bin
You choose the creature type you want to run with, and then either search your collection or Gatherer for all the creatures which match
OP-09 and OP-13 showed that English One Piece sealed product can move very differently from Japanese sealed product when supply tightens
He is already in your precon deck, so be sure to keep him around for the added card draw