Spirit of the Labyrinth doesn't work too well with Grisly Transformation or Underworld Connections

Sunbond is going to be way too difficult to get working because the only life-gain card you have is Gift of Orzhova . You should either commit with more life-gain tricks or switch it out for something else.

well then again...... you do have Ordeal of Heliod , Blind Obedience , and Tormented Hero sooo....... maybe it works for you?

Spirit of the Labyrinth isn't horrible with Underworld Connections since you can still draw on the opponent's turn, even tho that seems irrelevant now.

Anyways, I playtested this against my Standard Modern Jund: Welcome back DRS! deck, which has strong removal, and I went 4-1 against it. It seemed like you needed more protection since I was able to remove everything before it got out of hand, and Gods Willing was almost always my target for Thoughtseize . The one game you won was one where you got 3 Gods Willing and a Gift of Orzhova and were thus able to thwart my removal and bypass my creatures, and as I recall it was a Hero of Iroas that wasn't any bigger than 6/6. Since you're already maxed out on Gods Willing , you may want to add a couple copies of Brave the Elements or perhaps Boon of Erebos if you'd rather have a Heroic trigger and a way to survive Supreme Verdict .

Also, Sunbond was a completely dead card in the matchup. It always sat in your hand, got Scryed to the bottom, or was an overcosted Heroic trigger that did nothing. So that would probably be the first place I would recommend to cut to make room for more protection. Without Sunbond , you may want to switch out Ordeal of Heliod with Ordeal of Erebos since forcing your opponent to discard will be much more relevant in most matchups than life gain. In fact, in one of the games, you got over 30 life before I stabilized and it still didn't matter in the end since my board state was too dominant to come back from even if you had 100 life. Silent Sentinel was also never a factor in any of the games, as if it ever got to a point where you had 7 lands, the game was already over.

Finally, I would keep an eye on Odunos River Trawler . It was definitely a horrible matchup for that card since my deck has Deathrite Shaman and Scavenging Ooze to keep him from doing anything, but even then it seemed rare that its effect would be relevant even if the graveyard hate wasn't there. I would be tempted to fill that slot with Fiendslayer Paladin for a 3-drop with Lifelink and its own built-in protection from most of the format's good removal.

Otherwise, I enjoyed playing your deck, and the core seems really solid. Good luck! +1