I'm so torn on what to cut
#what to cut?
dry rivet
warm oxide
Shadow Kin is a cool card but doesn't exactly help with your strat to copy Vialsmasher. You're also not terribly interested in yards otherwise so milling opponents isn't crazy usewful
Beguiller of wills seems really slow and also somewhat unreliable
I think it might make sense to swap a few counterspells for onboard spot-removal. Some things will inevitably get through, and so having a few ways to handle stuff that's on the board could make sense.
a few cards that could make sense with the theme of the deck: [[snuff out]], [[Curtains' Call]] [[murderous cut]]
elfin swiftBOT
Instant
Undaunted (This spell costs 
less to cast for each opponent.)
Destroy two target creatures.
"We give the audience what they want." —Juri, proprietor of the Juri Revue
Instant
Delve (Each card you exile from your graveyard while casting this spell pays for .)
Destroy target creature.
warm oxide
eg, spells with decently high cmc that you can play for much cheaper
I also think that unless you're trying to play cedh, some of your conterspells are a bit too situational.
and if you are trying to play cedh, I think there's a lot more that needs to be changed lol
mirrormade could be a cut? It's cute, but you yourself don't have that many worthwhile copy targets for it imo, so you're mostly relying on other people playing cool stuff for you. In some games, it might just be manarocks
dry rivet
Shadow Kin is a cool card but doesn't exactly help with your strat to copy Vials...
oh she's there to copy someone else's thing, the deck isn't exclusive to copying my vial smasher, I much prefer cloning other people's shit and then make like 5 copies of that lmao, one time I had 6 copies of Koma lol
warm oxide
Sure, it's just that she's likely the least reliable clone
She might turn into something good
The thing with clone decks is that you shouldn't rely on your opponents on playing good clone targets
If they have something worth cloning, that's great. But you should still be able to advance your boardstate even if people aren't running anything crazy to clone. Sometimes they don't run many creatures at all, or their creatures are mostly 1/1 tokens, or they're very niche synergy pieces. In this deck, Shadow Kin is mostly relying on hitting something good from opponents, because your deck contains a good chunk of 0/0 clones and no other notable graveyard synergies
dry rivet
Yeah I agree about that one. Will cut. And maybe beguiler as well. I'm aiming for a solid 8 so I think the counters are fine. Might cut one for size though