The Lambent Horde

Sacrifice the Lambent Horde: Create a x/x Lambent drone creature token. Where X is the number of Lambent you control.

Delirium — Lambent drones you control get +1/+1 as long as there are four or more card types among cards in your graveyard.

Retrace (you may cast this card from your graveyard by discarding a land card in addition to paying its other costs.)