It turns out that Electroid + Steely Stare makes for a deadly combination.

This can be used on Darkmess Bowser and Bedrock too (takes a bit more to defeat Bedrock entirely though).

Wicked stuffff! The Edge and Bowser fight were extremely well done. Definitely a couple minute save.

Would've been faster if I'd used Edge for the dash and hadn't faffed around switching in Rabbid Rosalina when Mario could have made the jump too - always somewhere to improve I suppose!

Nice find