Hey so if for whatever of your MLB fanworks you need a battle song or a contemplative song you should use the songs from Hyrule Warriors: Age Of Calamity. The main theme (which is also a recurring leitmotif) is practically the same as MLB's.
For a contemplative/solemn/sad theme we have the various versions of "Overlooking Hyrule"
And for light fights (or I guess it works for anxious ones too, do whatever you want i'm not the boss of you) we have the training theme in Maz Koshia's shrine (iirc) "meditative training"
(I have no idea if these are actually the right one because I can't listen to them right now but I'll try to fix it if they are wrong or they don't play)
The game should have a few of these (all of the "Overlooking Hyrule" Variations are the main theme, the one during calamity is really slow tho so it's not instantly noticeable) since it's the main leitmotif, some are subtle and in the background, some are more obvious like the ones I put here. Some are not really fitting with the tone of Miraculous but still, even having just these two is useful imo