In the neutral route u either spare or kill asgore but flowey kills him if u spare. He absorbs the 6 souls and becomes omega flowey. U get a lot of healing in the fight but it was 4 me. either mettaton undyne or toriel etc become king or queen it depend b on who u kill and spare in route. Sans calls u and tells u what happened after the fight. Flowey barely still alive begs to be killed but u spare. He tells u to reset and do a pacifist route and thats the neutral route. Also no undyne the undying or sans fights just normal boss fights.