Arnett (dashed-lines) and CSM model (straight lines) fits to the bolometric LC of SN 2018bcc (blue). Since the Arnett models cannot fit both the bright peak and the rapidly declining tail simultaneously, even when accounting for gamma-ray leakage, we also show two examples of CSM-interaction powered model fits that can reproduce the bright and rapidly evolving peak of SN 2018bcc; the latter models use different parameters describing the CSM. Due to the caveats of these models (see text), we only use them to illustrate that bright and rapidly evolving LCs, such as that of SN 2018bcc, can be naturally produced by CSM interaction. The r-band upper limit has been included using the same bolometric correction as in Sect. 6.1.