Hi guys!
Got a bit tired of Grixis Delver recently and decided to play a little bit of RUG for old time's sake, trying to update it to modern standards.
After a few days of playing in the mtgo practice room I came up with this current build:

4 Delver
4 Mongoose
4 Mandrils(!)

4 Force
4 Daze
2 Pierce
2 Snare

4 Brainstorm
4 Ponder
4 Thoughtscour(!)

4 Bolt
2 Dismember

4 Wasteland
8 blue fetches
3 Volcanics
3 Tropicals

Sideboard:

2 Surgical Extraction
2 Pithing Needle
1 Pyroblast
1 Red Elemental Blast
2 Flusterstorm
2 Rough/Tumble
2 Ground Seal
2 Destructive Revelry (RIP and Leyline make this a must instead of Grudge)
1 Vendilion Clique


Mandrils and Mongoose seem really good against a lot of the other fair decks, especially 4c-control. The only issue against this deck is DRS, I found that going more than 6 removal spells really hurts the combo matchup though.
So I decided to go for the full 4 thoughtscour to power through the shaman, making use of Ground Seal postboard to combat decks that have deathrite, snapcaster and loam. The full 8 tough creatures allow me to board out the delvers in matchups that rely heavily on non-stp removal spells.
Thought Scour is also really handy post-sb against combo where it's often times draw-go and you don't have a fast clock without delver. This allows you to get cards in the yard without having to counter stuff just to fill your yard.

If you look closely you'll notice that I've sacrificed the holy cow and the reason that many people play RUG: Stifle!
Now, hear me out: Stifle can be pretty good, no doubt. The things we lose to though stifle isn't gonna stop: This is first and foremost Baleful Strix, but also Edicts, Planeswalker, RIP and Mass Removal like Deluge.
I've tried to Pierce and Snare instead 4 stifles, but ultimately I did way better with the split.
Note that pretty much everybody who's a bit smart will play around stifle as best as they can when they face RUG, it's not like Grixis where only half of the decks play that card.
Not only will people not play around Snare and Pierce excessively, we also only need to hold up these spells in the opponent's turn most of the time, meaning we can scour ourselves at the end step. This was not possible with stifle and led to some very weird mana-constrictions on side.

The sideboard is pretty straightforward:

2 Pithing Needles against Marit Lage because I don't have Edicts or bounce-spells. These matchups can be tough as nails otherwise. It's also really good against D&T and decent against Miracles and Sneak&Show.

Ground Seal is there to punish everyone who tries to stop us with deathrite or lock us out with Loam. It's also a "cantrip" that gets snapcaster and K-Command on their dead strixes. The fact that it's an enchantment is huge because unlike Winter Orb they can't just K-Command it.
Since I don't play DRS it's also good to have gy-hate #3+4, a pseudo-cage that can only be circumvented with exhume.

The clique is there against all those pesky decks that try to play draw-go until they have a critical mass, these games go long, so the anti-synergy with Daze won't matter too often. I won't bring it in against loam since I have ground seals.

Destructive Revelry instead of Grudge is a necessity because there's abunch of decks like Loam and Eldrazi that play Leyline, but also a few RIPs that can shut off our entire shroud-gameplan.

I don't play TNN because I don't feel the necessity: I already have 4 3-power shroud creatures, TNN also plays bad with our dazes and against opposing dazes and pyroblasts.


So yeah, while I don't think this deck is necessarily better than Grixis Delver, it's certainly still good, especially against the right meta. It's basically a delver deck tuned to combat anti-delver decks (4c-/Grixis-control, lands, Miracles).