Transmigrating to Another World with Heroic Spirit Cards and the Holy Grail

A certain Chiyo Yayu, who wishes to remain anonymous: "With Heroic Spirit cards and a Holy Grail packed with infinite mana, how could I possibly lose this round? I can even build a huge harem! Wahahahaha!"

"Oh my? A harem, you say? Don't joke around, Yayu."

"If you don't behave, you'll get a spanking!" Yin Hui declared.

"And another thing, Yayu, I'm running a little low on mana. You know what comes next, right?" Christina said.

"Yayu, marry me. I'll make sure to train you properly," said Wei'er.