Low to the ground aggressive ruby decks may not be at the top of the barrel in Immortal, but they can set people on fire and burn the metagame down when people lose respect for it. These decks use aggressively costed speed creatures to apply damage until the troops are dealt with or the ground gets gummed up, then switch gears to chucking burn spells at the face until their opponent is dead. Angus the Arsonist gives them a Ramunap Ruins level of inevitability since flooding out late game only means three damage is coming your way soon.
Comparable Archetypes in Other Games
Hearthstone: Aggro Burn Mage, Zoolock
MTG: Mono-Red Aggro, Sligh, Red Deck Wins
StorrowN’s Ruby Deck Wins (Immortal Weekly 3-0)