Thanks for your suggestions @ghoul_Legion and ticked-off-squirrel! I've added all of them to the maybeboard for now. I'll respond to them here.
The reason I don't add these cards to the deck rightaway is to keep the creature removal-LD ratio stable. When you play the deck now, most games you'll see you can remove nearly all the enemy's lands and creatures (dependent on your draws of course). Switching cards will change that ratio so I first want to playtest a bit before swapping cards.
What I'm mainly wanting to achieve with this deck is to make it a lot faster. It seems to be too slow currently against a lot of tier-1 decks (although there are also some it beats).
ghoul_Legion
--> Thunderous Wrath: This is something I'm playtesting with right now. I think this deck will be able to use the miracle effect quite a lot (as this deck doesn't use spells to draw) and I really want to add more cards to this deck to drain the opponents lives faster.
--> Leyline of Punishment: This cards seems to prevent something I've never really had problems with while playtesting. I'm not sure if this would greatly improve the deck.
--> Flashfires: Kinda like boil but for plains. Fun card, but there are just a few decks that are centered around only playing plains. I do see myself adding this to the sideboard though.
--> Boiling Seas: I currently have boil on my maybeboard. I had it on my sideboard. However, I could only board it in against very few decks.
--> Replace Pyroclasm with Flamebreak: Yes, I do need to reduce the opponents live some more. But the 3 red is about the worst cmc I could add to my deck. This deck already has way too many cards at 3cmc.
ticked-off-squirrel
--> Sulfuric Vortex: This one's not legal in modern. Would've been a great addition though.
--> Scorch the Fields: Costs 2 mana more (compared to stone rain) and does 1 damage against each human. Maybe for the sideboard against green decks, but 5cmc is a little too lategame.
--> Volcanic Upheaval: Costs one mana more (compared to stone rain) to make it an instant. I've been thinking a lot about this one, but I can't really think of many pros of having an instant LD.
--> Demolish and Vandalize: The artifact removal is great but the added mana cost is most of the time a pain is the ass. I guess I wouldn't play demolish because 4 mana just to remove an artifact is way too much. I guess I could add vandalize to the sideboard though because I play a lot against affinity and I really need artifact removal cards.
Also, I have added one more card to the maybeboard myself. I'd love to hear what you guys think of it:
--> Pyromancer's Goggles: 5cmc is much, but being able to destroy 2 lands or creatures each turn is a massive gain.
