('Bergentrückung', as heard in Bergentrückung)
'Bergentrückung' is the theme of Asgore, and as such is used to represent him in Bergentrückung, ASGORE, and Bring It In, Guys!.
Notably, 'Bergentrückung' seems to be based upon 'Once Upon a Time A', which is the single most prominent motif in the Undertale soundtrack.
Regardless, 'Bergentrückung' is specific enough to Asgore such that I'm comfortable covering it separately.