With a starting life total higher than 20, it becomes attractive to try to win the game through something other than regular combat damage. I spent some time thinking about how to build an infect deck for Tiny Leaders, and a lot of the spells that you want to play are legal. The major problem is that none of the existing leaders provide any actual value to your strategy.
There is, of course, no existing leader for Sultai. The rules of Tiny Leaders let a player play a 2/2 for UBG with no text if they wish to play this color pair, and if you want to play a strategy that doesn’t get any help from its leader you may as well play a leader that doesn’t help anybody. Not to mention that this selection of colors gives you access to all of the constructed playable infect creatures.
This is the list that I’ve brewed up for Sultai Poison:
This deck eschews some of the most expensive cards that you’d find in typical Sultai decks that make the Sultai leader inaccessible for many players, such as Dark Confidant and Tarmogoyf. I think that Snapcaster Mage is too good to cut, but it’s not entirely at home here.
I don’t play an Overgrown Tomb in my list, as the Golgari land is much less important than blue lands, but you want to be able to fetch for one land of this color pair. Realistically you could cut all of the revised duals and play Overgrown Tomb over Bayou for budgetary reasons.
I like the idea of fitting a bounceland or two into the deck, as if you have already drawn Inkmoth Nexus and you then draw Crop Rotation you can use the Crop Rotation to find a bounceland to save the Nexus from a removal spell.
Sideboards should definitely vary based on your local metagame. If you’re blue you should probably always have Blue Elemental Blast as every area has some red mages, but other than that your mileage is going to vary. I imagine that no matter where you are you’ll want a Spellskite though.