At the beginning of combat on your turn, if you both own and control Graf Rats and a creature named Midnight Scavengers, you may exile them, then meld them into Chittering Host

If you both own and control Hanweir Battlements and a creature named Hanweir Garrison, exile them, then meld them into Hanweir, the Writhing Township

Also need these tokens:
    14 Eldrazi Horror (TEMN) 1 (Eldritch Moon)
    24 Eldrazi Scion (DDR) 71 (Duel Decks: Nissa vs Ob Nixilis)
    5 Eldrazi (TPCA) 1 (Planechase Anthology)
    15 Eldrazi Spawn (DDP) 76 (Duel Decks: Zendikar vs Eldrazi)

The planes warp, bend, and tear as these unknowable eldritch abominations force their way into our reality. This Horde sucks all life out of your forces until there is nothing left. But that isn't the worst of it. If enough eldrazi seep into our world, nothing will be able to stop their titanic progenitors from traveling through space and time to devour reality itself.

Special Rules: All tokens controlled by the Horde have haste. All eldrazi spawn the Horde controls cannot attack or block. If the Horde controls 10 eldrazi spawn at the start of its precombat main phase, they are sacrificed, and the Horde casts the three eldrazi titans from exile.