Phantasmal Maelstrom

At the beginning of each end step, put the top
card of your library into your graveyard.
Delirium - Sacrifice Phantasmal Maelstrom: Return target card from your graveyard to your hand, then investigate. Activate this ability only
if there are four or more card types among cards
in your graveyard.
Where the drowned ones come to conspire.