Monster Chess

I looked at how the rules were implemented in greenchess. Here is what I found about questionable situations:

1 Stalemate for White. White can be in stalemate. In the position like above when White can make the first move that leads to stalemate, they are allowed to force stalemate, even if they have two legal moves.

2. En passant. En passant is possible only if the second of two last white moves where a moving pawn from the second to the fourth rank. It means that the order of White's move mater. If White move a pawn, and then, say, the King, then Black cannot capture en passant. In the following position, last moves for White was d2-d4 and f2-f4 in this order. Because of it black can capture f-pawn, but can't d-pawn.

3. Castling. Black can castle even if White threaten to capture Black King next move, as long as it is not check in standart chess. 

4. Stalemate for Black. Black can legally go in position where their King would be captured by White next move. So it means that Black can not claim stalemate, if the only option is to move into 5x5 square around the White King. E.g. the following is not stalemate, but it's loosing for Black. 

It's not what I expected, but at least it consistent. Two moves for Whites are considered as separated moves, not as one super move. So it makes sense. 

So...

He was wrong about en passant?

where did that 30 years of experience go(sry lol)

En passant only takes place after moving a pawn from  the 2nd to the 4th rank - as I stated.

En passant can not occur otherwise- ex: Black pawn on its own 4th rank can not en passant capture the White pawn moving two squares. Blacks pawn must be on its own 5th rank per regular chess rules.

Yes. Whites turn is two separate moves and not one “super move”

Keep in mind - no universal set of rules have been established. Obscure positions get left to interpretation until an agreement is found.