SLmanDR
Keepassx is actually keepassxc on Solus https://dev.getsol.us/source/keepassx/browse/master/package.yml
Keepass uses mono, Keepassx uses mono, keepassxc (Called keepassx on Solus) does not use mono.
Was that convoluted enough for you?
Basically install keepassx and forget this conversation took place. 😛
EDIT: reword to make an already confusing conversation less confusing