When Cleric Class's level 3 ability resolves, you gain life equal to the creature's toughness as it exists on battlefield, which may be different than its toughness in the graveyard
Any sustainable loop will be good enough, since even the smallest repeatable effect like Pyrite Spellbomb you can find on your board should be lethal
If you don't want to play a linear combo deck, however, Vito can still lead a strong lifegain deck, where you can stack similar effects like Enduring Tenacity, Starscape Cleric, and Sanguine Bond to gradually burn out your opponents
The error was swiftly corrected after the cards initial release, leaving a relatively small number of the first print run - known as Ancient Mew I among collectors - in circulation
Platinum / DPt era: Galactics Conquest - Advent of Arceus (Platinum - Arceus): Similar as the previous: both can be found in somewhat equal distribution between 1st and unlimited edition cards