MC fighting alongside lover
I'm a bit tired of the nonsensical 1v1 duels, teamwork fights are the best. Some authors have the bad habit of having people spread out into 1v1 instead of helping each other, the focus is all on superman fighting and looking cool instead of a believable fight.
On the off-chance that you're interested... basically in my story, Purger pairs are boys that have undergone brutal training since birth to kill monsters. The unique strengths and abilities of each duo usually complement each other.
Their relationships are quoted to be deeper than lovers, perhaps even too dependent on each other; if one dies, his partner will lose his will to live.
Sort of relative, I have a novel but it's only one scene where they are together as a Battle Couple.