I made this deck to try out how effective harbinger's CIP ability would be if it had Deadly via Kyrex Coach Driver. I usually add Deadly to harbinger by pulling it out though Jennev Merchant or Dark Return. It's been fairly consistent in mid-late games. As the combo only wipes out the opponent's board, it increases your odds of finishing the game with your existing units unless your peer is playing control.
Technically this combo only requires Feln fractions. But I've been enjoying the flexibility of TPS as a midrange deck (Fatties with inspired battle skills like lifesteal and deadly make the mass vs mass games more entertaining albeit it sucks against Skycrag, Stonescar, Hooru Infect and JPT Alessi )
Good for gauntlet grinding. Don't worry too much about prepping power. Crests and trail maker will suffice.