User blog comment:G-Monster/Pure Evil Proposal Demise/@comment-32039927-20200202225639

There is no actual implication that directly states that Demise is made of evil and therefore lacks agency. That's just something some people seem to have interpreted.

As for being "honorable" - no way. Demise compliments Link like three times, but considering he decides to curse Link's lineage and create Ganon as an incarnate of Link's hatred out of spite at the end of the boss fight, there's no honor left and there probably never was any, to begin with.