Are All Transforming Heroines Corrupted?

I've seen plenty of stories where people transmigrate and transform, but why are all my versions corrupted ones? I transmigrate and become Blackened Lancer Artoria, then trounce my uncorrupted self in the Fourth Holy Grail War. Huh? Why is the Rider Wade summoned Mordred? What do you mean, your father doesn't have breasts as big as mine?!

In a fake Holy Grail War, the one called Gudao, rejected by Human Order, is summoned.

"The Heroic Spirits you summon? I can summon identical versions, or even stronger ones~"

In the cyberpunk world, as the legendary V, I return to Night City and tear through Arasaka.

As a Herald of Destruction, Stelle brings ruin to countless worlds across the stars.

Wait, what do you mean Aunt Himeko is coming over with the Godslayer Sword to give me my final lesson?!