User blog comment:KrystalLBX/20 damage challenge (OTK puzzle)/@comment-26147696-20170529235050

First I would call Steel Rending Wings, Bladewing Phoenix, cast Reset Button then call Magical Beast Tamer, Kazane and Proto Golem, Jariim, next cast Oracle of Tuval and equip Magical Beast Tamer Flute, G'boy, next cast Secret Arts of the Water Lord(2nd effect) 19 life left, then use Bonus Quest and start attack phase, attack with all of your cards for 11 left then enter Final Phase, Call Bladewing, "Immortal Phoenix!" and attack for 4 more, you have delt 4 with it and then call Fake Keeper, Crimson Arrogant and attack.

Yes a lot of chance but it is 20 damage. you can also use two Dead End Crush! and deal 21 damage.