Currently on a 13 game winstreak with this in high Diamond and it's feeling fun as hell, so I thought I'd share this along with a few thoughts.
Consistency is the main problem here. It's decent at the minute and rarely loses to itself entirely but when pressured hard from turn 1 the deck definitely has problems. Thankfully the meta seems friendly enough at the minute to allowing a few turns to set up, and oh boy does the train ever get rolling fast if it gets to start.
A few ideas I'm tinkering with
It's possible that Makkar's Stranger belongs here, but I'm not convinced. All of the threats are pulling their weight and mass of card draw seems preferable to more killing effects.
The numbers of Dark Return and Xenan Temple might be wrong. I'm currently running 27 power, 4 seeks and 4 Trail Makers which feels nice, but might be a little too much fixing. Adjust as you feel.
Possible that Hailstorm in the market could be Downpour if you're finding a lot of Shrine decks, but that's a meta call.
The flex market slot is Mirror Image. I rarely get this, and if I do it's to mirror a 2/3 card Killer Feastcaller so the game is already basically over. Very open to suggestions on what could better be there.
Enjoy!