When Barrowin of Clan Undurr enters, venture into the dungeon. (Enter the first room or advance to the next room.)

Whenever Barrowin of Clan Undurr attacks, return up to one creature card with mana value 3 or less from your graveyard to the battlefield if you've completed a dungeon.

When Cloister Gargoyle enters, venture into the dungeon. (Enter the first room or advance to the next room.)

As long as you've completed a dungeon, Cloister Gargoyle gets +3/+0 and has flying.

Menace

Pack tactics — Whenever Minion of the Mighty attacks, if you attacked with creatures with total power 6 or greater this combat, you may put a Dragon creature card from your hand onto the battlefield tapped and attacking.

First strike

Sacrifice an artifact: Rust Monster gets +2/+0 until end of turn.