For the first part, you are correct though technically it happens in the other order (since you draw for turn first before doing anything else in the draw step). It is also not a discard. So, you draw a card, they mill 2. You then draw another card and then mill 2 again.
For Brainstorm, it would indeed cause Corrosion to trigger 3 times since you drew 3 cards. Each time you draw multiple cards, each is treated individually, so Brainstorm is really "draw a card", "draw a card", "draw a card".
Also, this is not a rumor and should be in the Rulings forum.
Could someone help clarify Psychic Corrosion for me? If I had a single Howling Mine on the battlefield and it became my turn, does the card draw from Howling Mine put a trigger on the stack for Psychic Corrosion and then my normal draw put another trigger on the stack to cause them to discard 4 cards in total during my draw step? Also, if a card like Brainstorm is cast, my opponent would only discard 2 cards since the wording says "when you draw a card" and not "each card" correct?
Could someone help clarify Psychic Corrosion for me? If I had a single Howling Mine on the battlefield and it became my turn, does the card draw from Howling Mine put a trigger on the stack for Psychic Corrosion and then my normal draw put another trigger on the stack to cause them to discard 4 cards in total during my draw step? Also, if a card like Brainstorm is cast, my opponent would only discard 2 cards since the wording says "when you draw a card" and not "each card" correct?
I also think 4 cards. Because otherwise, it will be worded as "Whenever you draw one or more cards"
You played JESUS?!?! I heard none of his guys stay in the graveyard, and once you think you have him beat he ALWAYS comes back to win within three turns. I like...WORSHIP him.
For Brainstorm, it would indeed cause Corrosion to trigger 3 times since you drew 3 cards. Each time you draw multiple cards, each is treated individually, so Brainstorm is really "draw a card", "draw a card", "draw a card".
Also, this is not a rumor and should be in the Rulings forum.
I also think 4 cards. Because otherwise, it will be worded as "Whenever you draw one or more cards"
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(W/U)(B/R)GForm of Progenitus, Shape of a Scrubland
BRGJund Tokens with Prossh, the Magic Dragon Foil
URGAnimar, the RUG CleanerFoil
RRRFeldon of the Third Path 2.0 Foil
BG(B/G)Not Another Meren DeckFoil
UR(U/R)Mizzix, Y Control and X Burn Spells
(W/U)(B/R)GHarold Ramos - The 35 Foot Long Twinkie (In +1/+1 counters)
UB(U/B)Dragonlord Silumgar