From the syslog in those first diagnostics you posted:
Mar 3 19:30:16 AlienBlood kernel: mdcmd (40): check nocorrect
Mar 3 19:30:16 AlienBlood kernel: md: recovery thread: check P Q ...
...
Mar 4 03:41:00 AlienBlood kernel: md: recovery thread: Q incorrect, sector=9867046256
Mar 4 03:41:00 AlienBlood kernel: md: recovery thread: Q incorrect, sector=9867046264
Mar 4 03:41:00 AlienBlood kernel: md: recovery thread: Q incorrect, sector=9867046272
...
From the syslog in these latest diagnostics:
Mar 6 21:30:34 AlienBlood kernel: mdcmd (40): check correct
Mar 6 21:30:34 AlienBlood kernel: md: recovery thread: check P Q ...
...
Mar 7 17:21:33 AlienBlood kernel: md: recovery thread: Q corrected, sector=9867046256
Mar 7 17:21:33 AlienBlood kernel: md: recovery thread: Q corrected, sector=9867046264
Mar 7 17:21:33 AlienBlood kernel: md: recovery thread: Q corrected, sector=9867046272
...
So, as you can see, that first parity check (nocorrect) found parity errors, but didn't correct them
This latest parity check (correct) found those same uncorrected parity errors, but it is correcting them.
When if finishes, run a non-correcting parity check and you should get zero parity errors.