The number of discard cards at your disposal is insane The sheer number of discard cards you can play is pretty incredible when you combine Amber and Emerald

Lorwyn Eclipsed Commander Auntie Ool, Cursewretch Blight Curse Ashling, the Limitless Dance of the Elements Edge of Eternities Commander Kilo, Apogee Mind Counter Intelligence Szarel, Genesis Shepherd World Shaper Final Fantasy Commander Tidus, Yuna's Guardian Counter Blitz Cloud, Ex-SOLDIER Limit Break Terra, Herald of Hope Revival Trance Y'shtola, Night's Blessed Scions & Spellcraft Tarkir: Dragonstorm Commander Felothar the Steadfast Abzan Armor Shiko and Narset, Unified Jeskai Striker Zurgo Stormrender Mardu Surge Teval, the Balanced Scale Sultai Arisen Eshki, Temur's Roar Temur Roar Aetherdrift Commander Temmet, Naktamun's Will Eternal Might Saheeli, Radiant Creator Living Energy Duskmourn: House of Horror Commander Winter, Cynical Opportunist Death Toll Valgavoth, Harrower of Souls Endless Punishment Zimone, Mystery Unraveler Jump Scare
Fourth, we have
The next reason is minor but not irrelevant and that is synergy, specifically with prowess effects which are popular in many aggressive red decks
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