Love this deck! There are a few cards I would suggest, firstly the mana base looks nice, but if your budget permits Verdant Catacombs would be ideal. I don't know how I feel about the Snow-Covered Swamp , as it really hurts to have a land that doesn't produce . Pendelhaven needs to go down to a one of in my opinion, though it is really awesome when you draw it making one want to play a playset, it is brutally painful when you have Haven1 and then draw Haven2. Inquisition of Kozilek is definitely a good reason to play in infect, and I feel that one card that matches well with it is Surgical Extraction , be it in the board or main deck, it allows you to target a fetchland in the opponents graveyard, look at their hand, and choose if you want to attack. If they have removal and you don't have an answer you don't have to attack, if the don't attack. Seeing you as semi-budget Surgical Extraction can be a bit expensive but it's on a down trend currently so I'd look at picking up a few copies soon.

Anyways, awesome deck, good luck brewing!

match_lighter: Thank you for your appreciation :)
For the manabase: the next plan is to go +2 Fetchlands, -1x Forest , -1x Snow-Covered Swamp . Since Forest and Overgrown Tomb are both fetchable with the "Forest"-keyword I can go for the budget version of Verdant Catacombs : Wooded Foothills / Windswept Heath .
The only reason to run Snow-Covered Swamp is against Blood Moon , which is not played very much, also i'd need a full playset of Verdant Catacombs to fetch is consistently. So neither my budget allows it nor have I the requirements by the Meta to play it.
(It allows me to play Inquisition of Kozilek and Plague Stinger , otherwise I would use the to animate Inkmoth Nexus ).
Regarding Pendelhaven : I upgraded to 2 last week and need to playtest. You increase the consistency of drawing it but also run the risk of beeing stuck with one on the field and one in hand. Need to see how the playtests go and then I'll decide if I go down to 1 again. 3 seems an overkill to me.
I never thought of using Surgical Extraction in such a matter, it seems like a good idea. Maybe I can borrow the card or proxy it for playtests, but currently it is out of my budget.

Torn666666: Thank you for the Upvote :)

zAzen7977 & ellie-is thank you for your upvotes, I appreciate them very much :)

Heya!

Considering the upcoming release of ONE, what do you think about the new toxic mechanic? Are cards like Venerated Rotpriest good enough to see play in modern? Or is the fact that toxic doesn't work with pump spells too much of a drawback? Is The Seedcore worth playing, even if you don't have a lot of 1/1s?

I'm exited to hear what you think.

SuckassBolas, the problem with the toxic mechanic is that it does not support the playstyle of using pump spells and there are not many cards in the current spoilers that I would consider having the power level that is needed for Modern. An interesting thing is that Infect and Toxic both trigger so you could play something like Necrogen Communion, but that card is still weaker than Rancor.
There might evolve a new deck where you mix Infect and Toxic creatures together, but I'm not the best deckbuilder.

Rotpriest looks a little too weak: you usually want to use 2-3 pump spells to win the game, so it would deal 2-3 infect damage and therefore is just another Giant Growth, but people are experimenting to create a storm deck with it using Ground Rift, here is the first list I was able to find.
The Seedcore is just a worse version of Pendelhaven: it does not produce , that is needed for pumpspells and we are already running 4 colourless lands with Inkmoth Nexus.

Maybe some of the Proliferate-Cards and cards where the opponent gets a poison counter might be playable, looking at Infectious Inuiry and Whispers of the Dross.

I'm still happy that the fastlands get reprinted and now can be played in Pioneer and The Mycosynth Gardens will probably become a modern staple.

Hope my 2 Cents are helpful :)