Activate the Sliver that can be cast using {B}{B} by sacrificing it, adding {B}{B}.
The Sliver is put onto the top of your library instead of into your graveyard due to the replacement effect given to it by Pulmonic Sliver.
Cast the Sliver from the top of your library by paying its mana cost.
Repeat.

Infinite creature LTB

Infinite creature ETB

Infinite storm count

Sliver Castable for {B}{B}

Pulmonic Sliver

Basal Sliver

Realmwalker

Activate Ashnod's Altar by sacrificing Metallic Sliver, adding {C}{C}.
Metallic Sliver is put on top of your library instead of your graveyard due to its ability granted by Pulmonic Sliver.
Cast Metallic Sliver from the top of your library by paying {1}.
Repeat.

Infinite colorless mana

Infinite death triggers

Infinite creature sacrifice triggers

Metallic Sliver

Ashnod's Altar

Future Sight

Garruk's Horde

Magus of the Future

The Reality Chip

Combos with "Pulmonic Sliver"