Haki and sword agenda raining supreme
Just like Rocks asked Harald to join him, Roger asked Garp to join him even though they are equals.
Seems like Zoro is showcasing new powers before they are explained. He did haki before it was shown. And now we have KoH shown before Roger showing his strongest attack which has massive haki, fire and named after his sword.
Also nice to have confirmation that the mountain destruction was done by WB.