I saw a really fun one in the arena a day or two ago that used unupped virus, fractal, and then soul catchers, ivory dragons, boneyards, etc. The idea was to save up for fractal, pump out 8 viruses, sac them, get quanta and skeletons, get fractal, then fractal a dragon. In the AIs hands it failed because it always fractaled the virus instead of the dragons, but I think a human could make it work. The viruses were purposely unupped because they were cheaper than retrovirus. (or that player was too poor to up them :p)
Even if you didn't go the fractal route, virus could work here. It would give you a bit of control, and even if you had a bad hand, you could play it turn 2 and sac it turn 3 to power your soulcatchers.
You could also be a jerk and use Shard of epic overpoweredness Sacrifice for more staying power. With the holy flashes, you could also play it at times when your opponent isn't expecting it. (35hp, play holy flash, get to 45, then shard and watch them squirm)