mtg cards like amulet of vigor | The Lost Caverns of Ixalan Commander Whenever a permanent enters the battlefield tapped and under your control Amulet of Vigor #103 Holo

Once The Soul Stone is harnessed, harnessing it again has no additional benefit

If an attacking creature you control goes unblocked, you can reveal a card with ninjutsu from your hand, pay the ninjutsu cost, and return that attacking creature to its owner's hand

This is similar to the Digimon card game, which Ryan Miller was involved in designing

#9 Gemstone Caverns Gemstone Caverns has only becoming a more popular option in Modern as of late

Creatures (14) Lands (25) Spells (21) Note that this is just one of many possible configurations for a new Standard Jund deck

For the most part, these function the same as sagas normally do, giving you chapter abilities for each turn that they remain in play, except they can also attack and block just like normal creatures