MTL - Tyrant Dragon Emperor - Chapter 7309 there's still one?

Ye Chen transmigrated to a parallel world. In this world, everyone who was 18 and above would enter a chat group named Monster Chat. From there, they would summon their pets.Each person only had 10 chances of summoning pets and one chance to form a bond with a pet. Right at this moment, a voice rang in Ye Chen’s head:[Ding! Successfully activated the Unlimited Summoning System.][Congratulations for summoning pet: Dark Princess (level 8)][Congratulations for summoning pet: Alchemist (level 7)][Congratulations for summoning pet: Female Asura (level 7)][Congratulations for summoning pet: Goddess (level 9)][Congratulations for summoning pet: Demon Fox (level 10)][Congratulations for summoning pet: Nyuwa (level 10)]……This was an era where humans, monsters and pets coexisted. This was also Ye Chen’s era.

The Empress who dies in torture, An Rushuang is her name. After she wakes up, she finds herself has time-travelled to when she was twelve years old, but she would turn into Major General’s white horse at night. He is a general who orders about the winds and clouds on the battlefield, and she is a little girl lives in her boudoir seclusively.
She endeavors to change her fate, and he spared no effort to win every battle. They meet each other every day, well, it’s night to be accurate. Is that a dream or not? She pleads to marry the seignior to win peace for her family, only to find he is the one she is going to marry.
“Growing old with you under the same roof is my long-cherished wish”, thought them both.

- Description from Novelupdates

After being awakened from their slumber, billions of people found themselves dispersed in various sealed crypts. Surrounded by earth, they each had only a shovel.

I got transmigrated into a game I’ve never seen before.

I thought it was a top-notch RPG and spent 30 years on it.

I retired as a war hero and planned to spend my remaining time leisurely.

But it turns out, it was an academy story?