All 6 Uses

however
in
City of Ashes
(Auto-generated)

She did not, however, push him away, and clearly taking this as a sign of encouragement, Simon slid his hand behind her head and deepened the kiss, parting her lips with his.†
Chpt 1 *

however = a word used to connect contrasting ideas as when using though, in spite of that, in contrast, nevertheless, etc.
However much Simon might appreciate it, it seemed early to break out the topless sleeping arrangements.
Chpt 5 *

however = regardless of how
Magnus, however, it seemed, had had enough.†
Chpt 12

however = a word used to connect contrasting ideas as when using though, in spite of that, in contrast, nevertheless, etc.
However kind her denials might have been, I do know one thing: She knows how I feel and she doesn't feel the same way.
Chpt Epil.

however = regardless of how
However spectacular the view, the man standing in front of the window didn't look particularly impressed by it.†
Chpt Prol.
However, there is something you should have.†
Chpt 4

Definitions:

(1) (however as in: However, complications may...)
though (or another expression that connects contrasting ideas)

Based on idea 1 we might not expect idea 2, but this is a way of saying that even though idea 1 exists, we still have idea 2. Synonyms include in spite of that, despite that, nevertheless, nonetheless, on the other hand, in contrast and but.
(2) (however as in: However much she tried...)
to whatever degree (regardless of how much; or whatever unspecified amount)
(3) (however as in: However you do it, get it done!)
in whatever way
(4) (meaning too rare to warrant focus)
Much more rarely (and arguably incorrectly), however can be used to intensify the word how, as when one says "However did you find her?" Grammarians would suggest using two words for that usage: "How ever did you find her?"