Adanto Vanguard is a uncommon Creature — Vampire Soldier card from The List (PLST), collector number XLN-1. Current market price: $0.39, TCGplayer market prices via Scryfall.
As long as this creature is attacking, it gets +2/+0. Pay 4 life: This creature gains indestructible until end of turn. (Damage and effects that say "destroy" don't destroy it.)