Legendary Creature Artifact - Necron Color tag templates(None) Jadar, Ghoulcaller of Nephalia At the beginning of your end step, if you control no creatures with decayed, create a 2/2 black Zombie creature token with decayed
The three other decks have easy-to-read win-cons with straightforward upgrade paths
Cards in near-mint or mint condition will generally command a higher price
Other than that it adds 5 black to devotion which you might care about, and is also a 5/5 indestructible which will probably come into play and get a bunch of +1/+1 counters immediately, so somewhat dangerous, but only if you can consistently cheat it out or generate all that black mana
Flying is amazing and blue has enough dorks for it to be able to build creature decks too
The Black one Overlord of the Balemurk costs five for a 5/5 with two-cost and impending five turns, that mills four and then you'll raise a dork/planeswalker to your hand from your 'yard