I just found it for you my friend, you needed to add a dash to the model numbers like this:
mfc-210c or dcp-115c
https://aur.archlinux.org/packages/?O=0&C=0&SeB=nd&K=dcp-115c&outdated=&SB=n&SO=a&PP=50&do_Search=Go
https://aur.archlinux.org/packages/?O=0&C=0&SeB=nd&K=mfc-210c&outdated=&SB=n&SO=a&PP=50&do_Search=Go
this one list’s both printers and matches the version from their site for the dcp-115c:
yaourt -S brother-mfc-210c
this one is newer but it only lists the MFC-210c, and matches the version from the site for it:
yaourt -S brother-cups-wrapper-extra 1.2.1-1
For the scanner (sane drivers):
yaourt -S brscan2
You can also use octopi to search for and install these as well, just click on in the right panel.