Fate/Re:Zero - Heroic Spirit Integration System (fanfic)

Transmigrated into the world of Re:Zero with a Grail-gifted system that allows him to integrate the power and abilities of various Heroic Spirits into himself, Orion makes his path through the plot while aiming to become a supreme existence. He starts with being only able to bring out 10% of his first integrated Heroic Spirit's power, but his Integration Percentage raises as he progresses through the plot and he unlocks more of his Heroic Spirits' powers, as well as acquires new Class Cards. Starting with Saber Mordred Pendragon as his first Heroic Spirit, Orion gets accidently pulled into the Royal Election, eventually deciding to become a new king of Lugnica, if only to fulfill the Special Bonus Quest and unlock a Ruler Class. **** It is not an AU. The MC is intruding into the original world of Re:Zero. - The System allows the MC to gain the strength and abilities of many different Heroic Spirits he happens to summon, making their strength his and combining all of their skills. At the start he only has one Class unlocked, but he gains a new Class Card with each passed Arc (for a total of Seven Main Classes from the Arcs + extra Classes from Bonus Quests + additional future unlocks for double classes). -The Heroic Spirits that the MC summons would be chosen 'randomly', prioritizing ones that he's 'compatible with'; though it basically translated to ones he likes, would get along with well or are similar to him. The auxiliary volume contains spoilers in regards to which Heroic Spirits he summons for each of the Main Classes. - Subaru is also there, but the plot is quite changed as he has a rather stress-free life as a side-character and secondary protagonist. - The MC has the ability to grant Lesser Grails to a few other people in the world, giving them the power to receive the powers of a Heroic Spirit they happen to summon. - The story will eventually include a harem, but it is not harem focused and there won't be much progress in the 'harem' department in the early chapters. (BTW, MC's main love interests are: Rem, Echidna and Priscilla, but his relationship with Emilia will also be quite special, and it's also guaranteed that he'd be quite popular with the other heroines. I'm not sure about Crush at this point, and if Orion would prevent her from losing her memories.) ///Tags: Servant Integration System///