These were named after the only four-color cards in Magic thus far, the Nephilim from Guildpact
Based on the alien villain from Final Fantasy 7 , Jenova, Ancient Calamity is a 1/5 alien legendary creature that costs four mana (two colorless, one black, and one green) to play
The combination of card draw and pressure is quite valuable, because the draw advantage gives you the fuel to end the game before your opponents find a way to get around it or to generate their own pressure
He can quest for two lore, has a strength of three and a willpower of six
While it is probably good enough in a deck that is built on the theme of +1/+1 counters, outside of this very specific archetype, adding a single +1/+1 counter to a creature just isn't enough value (even at instant speed) to make me add another tapped land to my deck, especially considering that green already has five MDFCs that I really want to be playing