So I ran the following deck to second place in a small 27-ppl event i Sweden a couple of days ago. I think there's some improvements to be done so any thoughts would be appreciated.

4 Gush
3 Preordain
4 Gitaxian Probe
1 Treasure Cruise
1 Ponder
1 Dig Through Time
1 Brainstorm
1 Ancestral Recall
1 Time Walk
1 Yawgmoth's Will
1 Demonic Tutor
1 Vampiric Tutor
1 Mystical Tutor

4 Force of Will
4 Mental Misstep
1 Flusterstorm
1 Cabal Therapy

1 Repeal
1 Swords to Plowshares
1 Abrupt Decay

1 Tendrils of Agony
3 Monastery Mentor
1 Fastbond

1 Mana Crypt
1 Mox Jet
1 Mox Pearl
1 Mox Ruby
1 Mox Sapphire
1 Mox Emerald
1 Black Lotus

3 Polluted Delta
3 Misty Rainforest
1 Island
1 Tropical Island
3 Tundra
2 Underground Sea
1 Library of Alexandria

sb
2 containment priest
1 sylvan library
2 swords to plowshares
2 spell pierce
1 nature's claim
2 hurkyl
1 tormod's crypt
1 rest in peace
1 pithing needle
2 stony silence

• The deck is weak against shops, and I'm not sure the sideboard plan works out. (It turned out to be actual 0 shops in the tournament.)
• I'd like to fit in Lotus Petal, possibly over the third Mentor. One more mana producer seems good, and it'd help a lot while going off.
• The removal suite (Swords/Repeal/Decay) might be a bit unoptimized. Decay in particular is bad for the mana base. Maybe a maindeck copy of Hurkyl? That helps as an extra small storm engine as well.
• Also unsure about the Therapy/Flusterstorm/Spell Pierce setup. My reasoning is that a single copy of Therapy would rarely be dead with the probes and mentors but a second copy might. Spell Pierce is mainly to help against planeswalkers because I lack Pyroblasts, but also against Oath.

Quite similar to a list I played in one of the early P9 challenges. I would cut mystical for merchant scroll.

I was considering that but chose Mystical for the opportunity to find Will or Tendrils while going off. I frequently side it out vs blue decks.

I played a list like this a while ago, I played a couple of thoughtseize, hurkyl's recalls and a regrowth main and didn't have probes or any removal. The deck was pretty good and the mentors give you a much better shops MU then you would have if you were only storm.

Didn't Steve Menendian play a Mentor Grow / Gush Tendrils list somewhere last year?

Something like his Pyromancer Grow list, but with Mentors, 2 Therapy, 2-3 Git Probe and 1 Regrowth?

@bips at least such a list is in his Gush book. I've played quite a lot with that list and it's a very potent list but folds to shops/spheres pretty badly.