The guardian

The explanation

Previously

"I knew it," said Inko as Uma then saw both Inko and Yagi crying "Mom, dad why are you crying," asked Uma "It's because your brother is home, Uma," said Yagi as Uma and Saber were surprised by the news. "What do you mean my brother's home I don't remember having a brother," said Uma "your right, and there is a reason for that but first I think it's best if we get everyone," said Yagi as got out his phone. Inko then went up to Saber and placed her hand on his helmet as he just stood there motionless. "Welcome back Izuku," said Inko as Izuku just looked at Inko.

Now

Timeskip

The people Yagi called came to the house and they were now in the living room the people that stood out to Uma were the principal UA Nezu who was a chimera or as others called him rat god, next was a lecturer from Magus Association Waver Velvet. "Now then I assume we all know why we are here," said Nezu as they looked at Uma and Izuku who was leaving again a wall.

"Uma, izuku do you two have anything to say" asked Nezu "Yes I want to know why you never told me I had a brother," said Uma "All alright it happened 14 years ago when you two were still young a man by the name of zouken wanted to take one of you and we knew he wouldn't give up that is when someone came and made us an offer," said Inko "who was this person and what was the offer," asked Uma "well first I am not a person per say and the offer was something that benefits everyone," said a voice as Uma and turned around and saw an cloaked figure.

"Who are you" asked Uma "I am the reason why you and your brother were separated and have no memories of each other. This shocked Uma and Izuku "I can tell you are confused so I will explain on the day I came to them with an offer to rid the world of zouken but in exchange, I wish to have Izuku, the reason being because I saw what he could become and your parents were reluctant at first but I showed them what he could become and they also told me it was his choice to make" said the figure.

"So naturally I asked Izuku who was unsure but you were the one to convince him in the end and he agreed but to make sure he excelled I locked both your memories," said the cloaked figure. "So what happened to Zouken and what was so important that Izuku had to be taken away" asked Uma "I destroyed Zouken easing him from this world and as for the second question it was to prepare the both of you for the holy grail war," said the figure "What is the holy grail war you guys keep talking about" asked Uma.

"The Holy Grail War is a contest, in which seven mages summon seven Heroic Spirits to compete and obtain the power of the "Holy Grail", which grants a wish to each member of the winning duo, and that mark on your hand proves that you are contestant for the grail," said Izuku as Uma looked at her hand. "I think I get it but how do we eliminate other mages do we take something from them" asked Uma as she saw the others looked uncomfortable.

"The only way to eliminate our competitors is to kill either the servant or the summoner," said Izuku as Uma was shocked by the news "So you telling me if we want to win we have to kill people," asked Uma "Yes there is no other way," said izuku as he could understand her as when he had to take a life for the first time. "I know this is a lot to process but it has started even now there are some mages summoning their servant, now then I will take my leave and unlock your memories goodbye," said the cloaked figure as it snapped its fingers and a small magic circle appeared on izuku's and umas forehead the disappeared.

Soon both izuku and Umas memories came back to them giving them a headache. "Are you guys okay?" asked Aizawa "Yeah we are okay uncle," said Izuku as he remembered everything now. "Izuku then sat down on a chair as he was still processing everything. "Izuku what did you do during the time you were gone" asked present mic. "Well that depends do you want the long or short version" asked Izuku "The short version please," said Nezu.

"Well the cloaked figure trained me day in and day out it showed me how to fight and use magic and the cloaked figure is an avatar of the earth's will and I was to become a guardian when I was old enough I was sent to different places throughout time where I was needed and was forced to get my hands dirty and I even participated in some holy grail wars," said izuku as Inko then walked over to him and hugged him. "I assume you won the grail wars," said Nezu.

"Yeah and my wish is always the same," said Izuku "What was your wish" asked present mic "The destruction of the grail," said Izuku surprising them. "But why would you wish for that you could have done so much good with it," asked Cementos "It's because I learned the truth about the grail," said Izuku "What truth would that be" asked Aizawa "The grail needs the blood of the masters and servant that were killed to activate" said izuku. The news shocked everyone they were speechless Izuku looked at his sister and saw she was horrified and he would make sure no one would lay a hand on her.

Hope you guys enjoyed the chapter