A sac outlet (Carrion Feeder) + a recurring zombie (Gravecrawler) + a death payoff (Diregraf Captain / Undead Augur) is your repeatable value loop assemble it and the game tilts
Literally no deck beat Elspeth when it landed
The deck is very mid-range in the sense that it can play aggressively and summon a lot of monsters, be a bit more defensively with Icarus Attack, or simply smash everything on the field with powerful synchro monsters
Nowadays, only Dark Magician and Blue-Eyes White Dragon are more recognisable, and they still hold a pedestal of power despite their legal varients competitive success
Because of that tension, its not a Top 10 card, but for your decks, its a strong adjunct to similar cards, such as Mortivore
So, if any of your Ultra Beasts find themselves knocked out, the Energy attached to them can still be put to use