Congrats on the win. I'm a big fan.
A couple questions about your deck:
1. What's the deal with the miser Pithing needle? Why?
2. Did you find Serum Powder to be worth 4 spots? It looks like you only used it a couple times.
Serum Powder was good to me all day and I know I used it a few times other than just vs the dredge decks. I can comfortably say I used it at least once, if more, during every match.
I haven't ran Trinisphere in my workshop builds for the last few years so I tossed in a Pithing Needle to see how it compared vs running the 3ball. I was going to use Phyrexian Revoker, but due to an enormous amount of creature removal in the format I chose Needle instead. Its provided outs vs late game Jace, TMS's, Vault/Key, Welder, Quasali, and a few other things. I've liked it so far and it hasn't been bad enough were I'm to the point of cutting it.