1. Play Cosmic Intervention during your turn.
2. Sac Flooded Strand.
3. Flooded Strand returns at the beginning next end step.
4. Sac the Flooded Strand at the end step.
5. Flooded Strand should then return at the beginning of the next end step of the next turn.
6. Sac Flooded Strand.
I don't think that will work more than 1 time. The next end step, is the end step of the next turn if you are already in your end step.
1. Play Cosmic Intervention during your turn.
2. Sac Flooded Strand. (the order of 1 and 2 doesn't matter)
3. You go to your end step. Flooded Strand returns.
4. Sac Flooded Strand while you are in your end step.
5. Your opponent turn.
6. End phase of his turn. Flooded Strand returns at the beginning of his end step.
7. You sac the Land but it will not longer return.
But I am not a judge. I don't know if the whole sac in my end turn thing is working like that.
Note that it says "this turn." The end step of your turn is this part of the turn. Since the card says "next end step" and not "your next end step," this would mean anything sacrificed during your end step (like in the Flooded Strand scenario here), will come back during the next possible end step after that, so your opponent's end step.
Elven Empire (and as predicted some of the commander legends elves were plants for this deck) Rhys the Exiled GREAT TIMING! it just spiked $20 because of kaldheim
Rhys, the Exiled is a Fluctuator from C20 situation where speculators thought there was no way it would be reprinted, but it was and now the price will crash hard.
Next, the new cards joining Wolverine Riders in the Elven Empire precon, led by Lathril, Blade of the Elves
Full decklists here.