Conquering The Game's World - Chapter 3: The Holy Dragon Knight.

Within the Immortal Realm, there were nine thousand major realms, with three thousand at the top, three thousand in the middle, and three thousand at the bottom, along with countless minor realms.

Xie Jingyuan, the master taoist of Qingxu Temple, was reborn into modern times together with the cat demon Su Miaomiao.

Su Miaomiao: That classmate’s dried fish seems delicious.

Xie Jingyuan: I’ll buy one for you, don’t steal it.

Su Miaomiao: It’s raining, Taoist Priest, come here and pick me up.

Xie Jingyuan: I’m busy.

Su Miaomiao: It’s okay, a male classmate is willing to drop me at the dormitory.

Xie Jingyuan: … Send me the location. ·

- Description from Novelupdates

Forge unparalleled mechs with the ambition of old age, and use the galaxy as a knife to smash the edge of the empire.

His name is Ji Xinghe. When he was 65 years old, he went to Alien Battlefield to avenge his son.

The old man is standing on the ground, his ambition is a thousand miles away, the old man wears armor, and fights to the galaxy, the old man drags his sword, it is not for glory.

- Description from novelbuddy

Jacob Steve, an Old Man, died at 116 after living a whole life.

But Jacob always had a dark side, which he always suppressed and hid from others.
However, in the later years of his life, when death was inevitable, he understood there wasn't any point in having wealth, knowledge, or desires if you couldn't have a life to enjoy them.

He became obsessed with fabled immortality and devoted his reaming life to extending his fleeting lifespan, but just like any other failed.

However, he mysteriously got another chance at life and found a way that led to fabled immortality.
But he was also forewarned that the way led to it was filled with blood and darkness!

In the end, Jacob chose it anyway with no way of going back, and it was also the start of his suffering and his icky, brutal journey toward the 'Immortality' he wanted so badly!