super rush headlong X super rush headlong?

Chain has nothing to do with this effect, because in the moment of the attack it doesnt matter which one activated first, both monsters have it's effect active.
So the attacking monster should win

the atking monster wins

both are destroyed.
It happened to me once. but sorry, I didn't take a screenshot of it

Anyone know why turn player priority would dominate over the standard chain effect order ?

That seems bizarre that this card would have some deference to the turn player, unless it's simple as that: a bizarre effect that breaks with standard rulings.

Don't remember what people who comment about chain said. These two is not interact with each other. Both are solve successfully and they're waiting for their effect. The turn's player (usual=the attacker) will effect first so you can just remember the attacker has the advantage from this card.

The game of Yugioh works in Chains!

It doesn't matter who attacks or who's turn it is.

What matters is how the chain is made.
The way the chain is made determines the way the chain will resolve!

So I will give you an example:

Lets say you active Super Rush first!
Than your opponent actives Super Rush after you!

The way it would look like in the game is the following:

Chain Link 1 - You = SRHL
Chain Link 2 - Opponent = SRHL


The chain link above shows who activated first and second.

Now comes the part of how to Resolve the chain!

The way the game Resolves the chain is by going backwards!

They will start with the person who activated last!

In the above example, Your opponent activated last which means he resolves first!

Resolve Link 1 - Opponent = SRHL
Resolve Link 2 - You = SRHL

Now when your opponent resolves his card first what happens is your monster will die unless your monster has an effect which makes him immune for that turn!

If your monster doesn't have an immune effect, Your monster will die.

Once it dies it would be your turn to resolve, but the problem is you can't resolve any more!

Your monster is no longer on the field so you can't resolve!

This is basically how it works!

the player with highest life points survives

It would be considered a chain, so the latest activated SRH would resolve first, rendering the other SRH useless.

The turn players SRH apply first and destroy the opponents monster, rendering their SRH useless

Player that is attacking has advantage