I would be happy to see a
Narcomoeba in this deck as dredging is unused in standard. You can mill your deck using
Diligent Excavator for example and make a use of
Necrotic Wound (need lots of historic card for that so it's hardly manageable). Search for Ascantza can be good to even if it puts only one card in the graveyard, but it skims through your deck so it's really powerful, as what you're looking for is that
X creature in the graveyard and all other pieces of the combo in hand. Milling your deck is hard to create an effective combo deck in standard, but
Stitcher's Supplier does mill a lot. I would also suggest putting a
Poison-Tip Archer in any deck creating an infinity of creature (even without attacking you can win, even just by poking), it can make the difference from a
Settle The Wreckage for example.
In fact I think that deck lacks drawing, because you mostly win with a combo.
Arguel's Blood fast main would be a no go because you can be against aggro, but Search for Ascantza is really neat here.
Karn could be good but again if you can't benefit from the
X/
X token with artifacts it's just an expensive drawing machine that may split your combo into
exile... What would be good is surveil so I would add the surveil musts like Discovery and
Thought Erasure.
Nightveil Sprite maybe ? I think it's too weak to surveil 1 each turn but you can test it out. And
Doom Whisperer might be a little too expensive (I would recommend one or two main though).
Price of Fame sided would be great too as it surveils.
Vraska's Contempt is also great sided (even though I know this deck runs beasts to kill, an instant killing even PW is something else).
Anyway this deck could be really cool if well constructed and even win against lots of other decks that lacks control (red, BG stompy, G stompy, angels). I would like to see it in play as I am looking for infinite combos too.