I'm fighting Kal'tsit? Really?

Reborn into a second life, Gerald, born into a noble family in Kazimierz, believes his future will be very bright.
This idea only lasted until he was imprisoned on the day he turned twenty-four.
During his leisurely days in prison, Gerald enjoys the most realistic dreams every night, inviting him to engage in physical battles with the biggest men in history. If he wins, he can obtain relics and embark on further challenges.
So he enjoyed a deep sleep in the self-destructive cycle of killing and being killed.
During his prison break, he was invited to the island by the green-clad doctor who had stabbed him through the neck in his dream.
—You mean, the general Felin who formed the three-nation alliance and fought against the Sarkaz army in my dream is this doctor named Kal'tsit?
—The banshee queen who sang my elegy has become this elite male operator from Rhodes Island?
—Isamara, who destroyed the world, is this Agor man with a heavy sword in front of me?
Hey! I don't want to fight you guys!!