It's true Damian may have wanted you as one of his generals, but he never, ever even hints at it, to my knowledge. Whether respect or scorn, he makes it clear you two are enemies and he aims to destroy you.
Either way, something's missing from how Damian handles the situation. If he wanted to destroy you, he wasted three opportunities. If his goal was to turn you to his side, he certainly never bothered trying.
The only solution I can figure is Damian is just making classic (poor) villain decisions, the evil to Zandalor's almost cartoony level of somewhat-hammy good.
