Brewing a UG Storm deck in Standard. Based on a Mono Green version I saw, adapted by myself and after testing online.
The deck works by creating a massive Marwyn with pump spells that also let you untap her, which you can then use to cast Rishkar's Expertise and draw loads of cards. Eventually, you will find a Wildest Dreams and use it to loop it all again. Finally, you attack with a massive, trampling Marwyn and one-shot your opponent.
Making this deck UG gives a few considerable benefits. First of all, you have a lot of card draw, which lets you cycle through your deck faster and much more consistently. As well, you can find either of the two big combo pieces (Marwyn and Rishkar's Expertise) with your card draw. Secondly, you get counter back-up (on top of Blossoming Defense) to protect your Marwyn and you can bring in Negate from the sideboard for further protection.
In true Storm fashion, you get to bring in Baral to make your spells cheaper and it makes the combo much more consistent. Most of your pump spells turn into almost Dark Rituals! Furthermore, the loot effect is sometimes relevant.
The land count is perhaps questionable, and the sideboard is basically all about protecting the combo (instead of fighting individual decks). Negate protects you from wraths and targeted removal. Deathgorge Scavenger to survive against Aggro (and Scarab God and Gift decks if they are still around much). Naturalize to fight against white enchantment-based removal. Nissa is an alternative win con and works remarkably well with the style of play (fixes your draws, acts as a mana sink). I could see her as a one-of mainboard option, too. Karn could probably work as well, but I haven't tested him at all in the deck.
