Watched the episode ; it was full of action and at last, the heroes have gone to the hyperspace;
However, this episode feels more like episode 49 than episode 29; this bttle seems to be the great battle that has been prepared through the whole series.
I guess there is gonna be other enemies afterwards, but Messiah has always had a "Big Bad" feeling, with the fght against him being the "Final Boss fight"; and the all the previews telling the audience "final battle " don't help either.
Taking another example of a sentai series which had a good bunch of main enemies who were defeated halfway through the series (Turboranger, which had also a big ratings decline compared to the previous sentai), in that case, they kept the Big Bad, so the fight didn't feel "final fight" in that case.
As a result, that arc seems pretty puzzling, and I even feel that it's somewhat rushed.