Count to 10.
First off, a lot of credit to Moobu for his deck 20+ Damage on turn 3?
Deck runs off of combos with prowess and kiln fiend. Splash black to just go for 10 instead with Tainted Strike otherwise
Assualt Strobe
is needed for lethal damage. Monastery Swiftspear and the right cards are possible to kill turn 2. Turn 3 kill is more likely than this with all of the pieces of the combo in your hand. Being that of Assault Strobe and Tainted Strike. Slip Through Space and Apostle's Blessing can help you swing through unblocked. Than you have Gitaxian Probe, Manamorphose, Slip Through Space and Remand for card draw. Remand is also for stopping removal, save the mana for turn 2 to wait to go off on turn 3. Manamorphose into a Remand is always fun. Mutagenic Growth for extra triggers from prowess and Kiln Fiend. Gitaxian Probe lets you know what your up against and replaces itself as well, play usually before a creature unless you have more than 1 in hand. With all the card draws you don't need to worry about your tutor from Flamekin Harbinger.
Turn 3 Kill
Turn 1
Shock land entered untapped, or possible Monastery Swiftspear or Flamekin Harbinger
Turn 2
Land, Remand or Kiln Fiend.
Turn 3
If either of the creatures are now alive on your turn, and you have the covereage from Apostle's Blessing remaining in your hand for removal, start your combo with Manamorphose or sorceries like Slip Through Space, assault probe, and Gitaxian Probe. This is usually when they respond, wait for one before you cast Apostle's Blessing. Tainted Strike, Apostle's Blessing, and Mutagenic Growth for after and responses or before damage. All you need are 3 triggers from Kiln Fiend for lethal with Tainted Strike or assault probe.
Prowess Turn 3 Kill
Prowess you need more triggers but is possible, Mutagenic Growth gives it +3/+3 and being that it can be -2 life for free helps a lot, and Tainted Strike +2/+1. Assault Strobe
+
Tainted Strike
with Apostle's Blessing or Slip Through Space is lethal, but getting to 10 doublestriker unblockable without infect is slightly harder, enough cantrips, or Mutagenic Growth. Would take 6 triggers with no buffs, Mutagenic Growth speeds this up greatly, by acting as 3 triggers. You can Assault Strobe, Slip Through Space, and hold a mana for Apostle's Blessing. It is now a 3/4 or 3/5, now phyrexian mana cards, 2 Mutagenic Growth is the easiest, but with Manamorphose and Gitaxian Probe being 'free' cards can get you where you need. 3 of either 1 of these and a Mutagenic Growth can make lethal.
Prowess Turn 2 Kill
Turn 1
Land and Monastery Swiftspear attack for 1 if on the play
Turn 2
Land followed with Assault Strobe
+
Tainted Strike
, and a Phyrexian mana (or Manamorphose) card. (Play main phase 1 if sorc.) for the last prowess trigger to make is a 5/5 doublestriker. This is very slim though due to the fact of a possible blocker and removal, but if an aggro hasty guy comes out this is easier. Assault Strobe may not be needed with enough Mutagenic Growth
