Fate/Hentai System Fate Verse R-18

Alex [MC] who was once an assassin is reborn as Shirou Emiya's brother with Hentai System, having the power to summon more than 1 Heroic Spirits and even the ability to have unlimited mana as a Master of Servants. Think of a the Hentai System as a Gacha System but with more lustful hentai powers and skills. Alex can also travel back in time in Fate Verse to make contracts with Heroic Spirits!
Will the MC select the good or evil route? Will he rise to become the most powerful Master Magus in existence? Will he crush Gods and Battle in the Holy Grail Wars to come? His Journey Begins.

[Timeline]: Fate Night Stay + Fate Zero, will change over time to Fate Grand Order

[WARNING!]: This fanfic will contain heavy dark R-18 content. Sexual and Gore content as well as abuse is in this fanfic. I am writing this to see how big of a harem I can write so expect lots of R-18 content. Also there might be genderbending, I want to write Astofo getting fucked.