Here's Mesogog

Here's the last Monster-of-the-day in the Fortress

Here's maybe new footage of the Monster as seen on the Computer Monitor
however after looking through things, I don't know whether it's new or
not

Shots of scene
which could be new.
Here's definite Sentai footage

New

Sentai

New

Sentai

New

Sentai

New

Sentai

These shots
are something that I'm unsure about but I'm
mostly unsure about the Black one. I'm kinda certain the Red one is
Sentai.
However here is when it definitely goes back to Sentai

NOTE: All Sentai footage featuring Mesogog's last Monster-of-the-Day
comes from Abaranger 48.