In future chapters like chapter 60 -80, while Layla the regressor tries to stop group of the lab members. Aeon encounter a woman looks like Layla but not Layla she has Black hair lean toward dark red-violet hair colour and with violet eyes colour whereas Layla has black hair and green eyes.
Layla's sister will make her first appearance. She would have an epic thrilling fight with Aeon. life death fight. Layla older sister, name is Sera. she taken a like to Aeon and admire Aeon's tactical strategies and plans that push more than half of the mysterious lab organisation to the brink of destruction.
she was winning the fight at first but suddenly the table turned around and she was losing badly. at the last second, a leader of the organisation interferes. they bomb the place which causes Aeon act like it make Aeon disappear after an accident in a near-life-or-death situation against large horde of zombies and the lab mysterious organisations leaders. He miraculously survives, but others don't know that he did, nor do they know his whereabouts. everyone continue their struggle. after the group gets in a dangerous situation a masked man come and save them but then disappear. and this cycle repeat where they get in danger and a mysterious masked man appear and get rid of the problem. the mysterious masked man is Aeon in secret. in an emotional life-death situation where Aeon protect everyone his mask cracks but still on, So Layla only gets a glimpse of his golden eyes. She wasn't sure and she doubted what she saw, a golden eyes!, could it be ... Aeon? no way we all thought he died but there was no corpse... if he survived and all along was actually alive, Layla questioned why didn't he come bak to us? it seems he has a purpose. Sera show up now and then many times. in the end Aeon heroically as a zombie player crush everyone with his skills. he tricked everyone and he won at the end. everyone shocked by his unexpected acts and actions. some are happy he's back. Sera was held captive but she admitted everything, that her mother which also Layla's mother. is held captive to cooperate in making a medication that can increase life span and physical regeneration for example if someone injured, he can recover by self regenration. and also strengthen the physical body. although it looks beneficuial to humans. the poeple trying to create it are trying ti use it for bad purposes and to rule the people living. Layla's mother refused to cooperate in creating such a medication. but they threatened her with her family, relatives, and even strangers. by telling her if she didn't cooperate then they would kill or kidnap strangers.
important note; Aeon is a zombie player, he played a zombie VR game created by Ai that describe the zombie outbreak that is happening. in the game there are missions and quests that increase survival rate of the player. and it guides towards how to create a vaccine.
Layla is a regressor who regressed 5 times. she became cold, merciless to everyone because she knew that some people are selfish, and some are dependent if you help them. and some will betray, and even if she helped them, they would die. so, she decided instead of helping others. she must focus on the mission of finding the hidden masterminds and culprits who caused the zombie outbreak and kill them to end the suffering. she notices in her 5th regression that Aeon act differently from others. he is clear headed, cold, mysterious, and it feels as if he know what he should do, as if he has clear purpose and an already prepared plans. so she decided to get to know him and make him reveal his secrets. throughout the story, the relationship between Layla (the regressed heroine) and Aeon (the zombie player) will develop from strangers to classmates, to Campanians to friends then to close trusted friends then special friends then to liking and admiration then to love.
Sera is Layla's sister, she is only one year older than her. she works for the lab mysterious organisation only to protect her mother from them in case they try something, but she doesn't have the ability to destroy the organisation and she fear if she did try to do a reckless plan then her mother and her sister will die. after meeting Aeon and fighting against him, she takes a liking to him.