500 years booster box in the Future - Get ready to power up your collection with EB 500 Years in the Future

When your opponent activates a card or effect on the field (Quick Effect): You can send 1 face-up "Ashened" card you control to the GY

Even with just Mikanko Ceremony and Curse, you can Ritual Summon from the deck using Curse as a cost, tribute the Mikanko Ritual Monster to self-revive Curse, and search for a Mikanko card, which technically works as a starter

Modern online trading card games are nearly always an online service, constantly updating with new mechanics to learn and cards to buy

I don't get why I would want to do that to get me to a win

You may not wait and cast it later in the turn (unless of course the ability triggers and resolves again).