War History is an AU of what i think happened in the war between humans and monsters
Humans were afraid of monsters since if they absorb a human soul they can become a god then the king stroked war upon the monsters.
King Theseus the VII
The legendary Viking wanted greed and land he heard monsters had tons and they can be a easy way of getting stronger killing them. so wanted to help prince Edward the VI kill all the monsters but 11 years later in the war he captured by the monsters and later killed for a peace offering.
Prince Edward the VI
He was scared of the monsters and asked the general to start a war then early in the war Undynes mother (Helena) shot one of his eyes out then he killed King Parmius (who was the king of monsters before Asgore) but one day he eye got infected and passed away 4 weeks later.
King Henry the X
The Farther of Edward was furious that his son died and he stopped the war knowing how bad it became but died 12 years later by Theseus nephew Zelimir
Theseus Nephew took full control after Henry's death and attacked on Christmas day when they we're vulnerable (lots of dust came on the ground that day and he was the most hated) his guardsmen hated him and rebelled onto the monsters side. then 3 years later after the rebelling a monster managed to get in the castle and kill him. but his wife (Artiga) was angry so when she became queen she called the Spanish King for help
She's the warrior she made every solider go on her side again Toriel hated Artiga and Toriel took control off the monsters so she will die but she knew she can't last for long since she controlled them so she asked the Spanish king Juan Carlos II to put them underground
Juan Carlos II
after many deaths hes the one to kill them all then he got the 2 wizards to create then Barrier he executed the monster lovers but one monster didn't get get inside and he slaughtered him peace by peace that person was Undynes Farther, then she was turned to dust by a solider.
the old king and the father of Asgore and Toriel he just wanted peace but the humans were violent so he told the monsters to go rouge and be what the humans say we are but 1/2 year later he was killed by Prince Edward VI.
He followed his fathers footsteps just tried to spare them but they kept fighting back more then he had to make his soldiers fight till their last breath and tries to make Toriel fall in love with him
She normally was a medic helping Gaster but she was fierce and when SHE came she wanted control to end her life because Toriel saw no good in her. Asgore tries to impress her so she can be Queen of Monsters
it was W.D Gaster he worked hard reviving monsters and creating them for battle but when his wife died by a human she created the Plague (the black death) which was really deadly and helped the monsters out alot
The wife of Gaster she shortly past away after loosing a human then was surprised attacked by them but her soul is still alive broken or not
hes still a baby Gaster was going to make him a Strong monster by made the weakest with 20 hp and 1 AT and 1DF
Puiltag (Undynes farther)
he was the General of the royal guard and killed Juan the II his fighting spirit was passed on to Undyne.
Helena (Undnyes mother)
she used a bow and she was helpful and supported everyone and shot Edward in the eye people said she was secretly the goodness of war.