yes it needs 6 soul catchers.
i fooled around with both versions, DoSA and Retro.
both are fun to play, but to be honest, both decks suffer on bad draws.
and there is a reason for that, lying in the nature of both decks:
you need almost every kind of cards in the deck early, to get a succesfull combo
-> no SC: bad -> outrushed
-> no towers: bad -> outrushed
-> no virus: bad -> outrushed
-> no bonewall: bad -> outrushed
oh... and fractal is also crucial.
also every early delay, a fg manage to do (concealing or lobo your virus/exploding or quake your towers, sc's), takes your setup in a high vulnerable position.
but, you are able to beat almost every fg with this deck. osiris, decay and scorpio are the only fgs i coudnt beat so far.
the stats i took so far seems to have a win% about 25-30% (im gonna post them later).
anyways this decks are a really nice alternation to rol/hope