Onslaught

{T}, Pay 1 life, Sacrifice Wooded Foothills: Search your library for a Mountain or Forest card, put it onto the battlefield, then shuffle.

({T}: Add {R}.)

({T}: Add {U}.)

Grand Coliseum enters the battlefield tapped. {T}: Add {C}. {T}: Add one mana of any color. Grand Coliseum deals 1 damage to you.

{T}, Pay 1 life, Sacrifice Flooded Strand: Search your library for a Plains or Island card, put it onto the battlefield, then shuffle.

({T}: Add {G}.)

({T}: Add {W}.)

({T}: Add {R}.)

({T}: Add {G}.)

{T}, Pay 1 life, Sacrifice Windswept Heath: Search your library for a Forest or Plains card, put it onto the battlefield, then shuffle.

{T}, Pay 1 life, Sacrifice Bloodstained Mire: Search your library for a Swamp or Mountain card, put it onto the battlefield, then shuffle.

{T}: Add {C}. {R}{G}, {T}: Target Beast creature you control fights target creature an opponent controls. (Each deals damage equal to its power to ...

({T}: Add {B}.)

({T}: Add {G}.)

({T}: Add {R}.)

({T}: Add {G}.)

({T}: Add {W}.)

({T}: Add {R}.)