u/HappyGlobe

I’m wondering about the following situation:

1.) I have Ashnod’s Altar in play and three thopter tokens on the board.

2.) I cast Discerning Riddler, which has the text, “When this creature enters, you may discard a card. If you do, draw a card.“ I discard Emrakul, the World Anew, which has Madness 6.

3.) I sacrifice my three thopters to generate 6 colorless mana.

4.) I cast Emrakul, the World Anew with the 6 colorless mana.

5.) I then draw a card and the Riddler’s ETB resolves.

Would I be able to Ashnod’s Altar in the middle of that ETB’s resolution? My concern is that since the discard happens before the ETB has finished resolving, I wouldn’t be able to activate Ashnod’s Altar in the middle of it all.