400 Years After I Was Summoned My Childhood Friend Got Summoned Too

More than 400 years has passed since Alex Brandt was summoned in another world and became the Hero. He fought Against the Demon King and his mighty armies and defeated them after a long and arduous journey.
Shortly after he saved the world Alex retired from his heroic duties and started a family. Life seemed to be smooth sailing for him then but life isn't always sunshine and rainbows.
A civil war broke out in the Kingdom he and his family were living in and his family were among the many victims that perished during the civil war... Struck with extreme sorrow, grief and anger, the Hero singlehandedly ended the war only to suddenly disappear shortly after.
Now after centuries passed it seems that the string of fate still seems to play with him for one night while overlooking the forest, he caught sight of a large pillar of light.
The pillar of light he recognized as the one from his Hero summoning, and what he finds there was his childhood friend among many others.

AN: This is my first ever novel and so there may be a few (A LOT) of spelling and grammar mistakes so feel free to point them out at the comments section and I'm still a freshman in college so I don't have a proper schedule for uploads and I'm just doing this on my free time. I'm also posting this in WEBNOVEL, same title but under the name of Beamingkangaroo.