Edited in her subject number and changed her alias; I was half-asleep when writing this and it didn't occur to me at the time that it would be a name she'd give herself, and I don't see any reason she'd name herself Switch right off the bat. (And yet I realized this at midnight...?)

As for the combination logic, it was like her brother's power overwhelmed his body, slowly breaking it down. When there was only a small amount left, mostly brain cells and energy, they injected it into Charity's brain. So technically he would be dead anyway and lives on in his sister.