At the beginning of your upkeep, put a +1/+1 counter on Gozogebdephyl for each Vampire you control, then sacrifice one
At the beginning of your end step, remove all counters from Gozogebdephyl. Target player loses life equal to the number of counters removed this way, you gain that much life.
Whenever Gozogebdephyl attacks, you may exile the top X cards of your library, where X is the number of +1/+1 counters on Gozogebdephyl. When you do, you may cast all Symbiote cards exiled this way until end of turn, without paying their mana costs.
The Old Oligarch of SYMBIOSIS