Take it off the shelf and put it on the table.

I don't have any great advice but I am curious about your partner's feedback, what is it that they dislike about the game? Is it this game in particular or card battlers in general?

I'm not sure what is exactly the reasons you don't play it. Is your partner no interested in the game? If so, why? Depending on the reason such as it is intimidating, it might take too long, cba to learn a new game right now, wants to play a different game etc. a different approach could work.

One general thing that has worked for me is to just put it on the table. On a free evening where both of you have no plans when the question comes up what you want to do today just say. 'I'll take another look at mage wars arena.' this way they can't say no. Because it's just your plan. You didn't ask to play. Now if they show interest you can ask if they want to join in. Or they might ask themselves.

Thing is no matter the reaction in the designated time you put the game up, prepare everything, read up some rules etc. Usually my partner would come over and see what I was doing and eventually join on. Everything is already ready to play after all. And if not I'd maybe play vs myself for a turn or two and eventually ask if they wanna join in. If even then it is a no then it won't becomes a yes and I'd ask friends to play the game next time.