Aang and La, Ocean's Fury Abaddon the Despoiler Aberrant Aberrant Manawurm Abominable Treefolk Abomination, Irradiated Brute Abomination, Terrifying Titan Abomination, World Ravager Abyssal Persecutor Advent of the Wurm Aetherstream Leopard Aetherwind Basker Agatha of the Vile Cauldron Agatha's Champion Agent Frank Horrigan Aggression Aggressive Mammoth Agonasaur Rex Ajani's Comrade Ajani, Valiant Protector Akawalli, the Seething Tower Akoum Stonewaker Akoum Warrior Akroma's Memorial Akroma, Angel of Fury Akroma, Angel of Wrath Akroma, Angel of Wrath Avatar Akroma, Vision of Ixidor Aku Djinn Akul the Unrepentant Alexios, Deimos of Kosmos Almighty Brushwagg Aloe Alchemist Alpha Deathclaw Altanak, the Thrice-Called Altar Golem Altar of the Goyf Amarant Coral Ambush Krotiq Anax and Cymede Ancestral Anger Ancient Imperiosaur Ancient Stone Idol Ancient of the Equinox Anep, Vizier of Hazoret Angelfire Ignition Angry Mob Angry Rabble Annoyed Altisaur Ant-Man, Reformed Rogue Appeal // Authority Appeal // Authority Arahbo, Roar of the World Arbalest Engineers Arborback Stomper Arcane Archery Arcbound Crusher Archdemon of Greed Archdemon of Unx Archetype of Aggression Archon of Valor's Reach Archweaver Arctic Nishoba Argothian Swine Argothian Wurm Arlinn, Embraced by the Moon Arlinn, the Moon's Fury Armada Wurm Armadillo Cloak Armory Paladin Arrogant Wurm Ashroot Animist

Even if you drop a Yellow deck's life pile down to one, that could easily just turn into a three-card life pile on their next turn
However, all it takes is one game with him to realize just how much damage he ends up dishing out
Casually, yes, as long as your fellow players are specifically okay with them