The deck has two paths to an infinite kill combo on turn 4, and another for an infinite tokengen combo on turn 4, each hinging on sidestepping a different shutdown mechanic.
Artifact based (direct damage / sorcery speed / resolves 1 damage a time / targeted; vulnerable to storm):Gravecrawler>Blood Funnel>Blasting Station(sac Gravecrawler for BF, spend other two mana on any creature)>Rooftop Storm+any zombies in hand for free to retrieve GC if one is not on the field already
or Creature lifeloss based (not direct damage / sorcery speed / resolves 1 life lost at a time / targeted; vulnerable to storm):Gravecrawler>Blood Funnel>Diregraf Captain>Rooftop Storm+Grimgrin, revive GC
or Creature spam (direct damage / combat / targeted):Gravecrawler>Skirsdag>Liliana>Blood Funnel+Intruder Alarm(sac GC)
Getting Blood Funnel shut down pushes the Rooftop Storm back a turn for Creature lifeloss, but does not affect Artifact's turn4 combo if another Blood Funnel is played on turn 3.
Vulnerable to enchantment based Hexproof:Sideboards Kheru Bloodsucker (Diregraf+Diregraf, or infinite tokenspam, with Kheru to re-enable the Creature lifeloss combo).
Vulnerable to Grapheshot:Sideboards Mindbreak Trap to deal with Grapeshot reversal on Artifact/Creature combo.
Vulnerable to targeted exile (Surgical Extraction): if Gravecrawler is tagged without a Gravecrawler hiding somewhere it won't be exiled (e.g.- in hand or on board for Surgical Extraction), only Skirsdag+Liliana combo remains viable (sac'ing anything flips Liliana, provides a zombie token and Liliana can bring back the sac'd creature to provide the two bodies needed for Skirsdag to tap and create a 5/5 flying; token entering the field untaps all your creatures, rinse and repeat endlessly then attack the next turn or burn them to Blasting Station played on turn 5).
