Whatupmyfellowkids
thanks for the awesome chapter author san and you have utilized the seals to there maximum and very few author do that so please continue with this amazing work. and just asking out of curiosity how will Mc get eternal mangekyo, because without it he would become blind and eternal mangekyo is also stronger than a regular mangekyo, well except obito's that is.
To advance the sharingan you need to experience an excessive amount of negative emotions/emotions in general, train, or get indra's chakra/otsutsuki chakra. Every Uchiha who activates the sharingan has a small amount of Indra's chakra so if the MC can single out Indra's chakra and absorb enough of it he can theoretically advance his eyes to mangekyo and maybe eternal