I was wondering about luks encryption, if I were to, say, encrypt my drive, boot into the system and put in the unencryption password to gain access. No I have access to the unencrypted files.
If a malicious person accessed my system while it's runnig would the files as is (unencrypted)? Or would he also require the encryption passwordto be able to make sense of the data?

Again this is during normal operation of the device with the encrypted drive mounted and accessed