Been rewatching the final battle and just had some observations I would like to share with everyone.

1. Beam consistency Both beams (Gagula and Gridknight Dynarex) have been consistent in their nature and power level. Well, besides the obvious, for plot purposes, both beams did not immediately annihilate their targets. Kaiser Gridknight did not vaporize or explode upon being hit by Gagula's beam. The Blazing Inferno Dynarex Roar also did not vaporize Gagula instantaneously, hence, the need for the Gridknight punch and Dynarex headbutt.

2. Why the Blazing Inferno Dynarex roar seemed more powerful and the Kaiser Gridknight beam (forgot the move's name) doesn't For those wondering why Kaiser Gridknight's beam did not overpower Gagula's beam and why the Blazing Inferno Dynarex roar (which requires 2 mechas) managed to finish Gagula, here's the answer: damaged in vital areas. During the battle, Dynazenon hit Gagula squarely in the chest (which appears to be its core) with the Dynazenon full burst. This was followed by Gridknight Goldburn damaging the spines of Gagula with a kick on the back. By the time Gagula was hit by the Blazing Inferno Dynarex Roar it was already severely damaged.

3. Why the punch and headbutt seemed to have finished Gagula (Correct me if I'm wrong in this one). Some might be wondering why a simple punch and headbutt seemed to have finished Gagula and the Eugenecists. Here's my theory: the Eugenecists are placed inside Gagula's head. When they were "eaten", it's possible that the Eugenecists were placed inside Gagula's head and not the power core on its chest, otherwise the full burst would have finished them. This, and the fact that Gagula would have started disintegrating from the beam (remember the beams do not instantaneously vaporize their targets) lead to the kaiju and the eugenecists' demise.

4. Why Yomogi's instance domination worked Because he's Yomogi, that's why. Lol. Kidding aside, Yomogi's instance domination worked but only for a couple of seconds since he's overriding only one instance domination (Shizumu's). Remember, the other eugenecists were simply "absorbed" but none of them also used instance domination. Yomogi's instance domination is also consistent with the fact that we're shown in one episode that stronger kaijus would require 2 instance dominations. Considering that Gagula, a powerful kaiju, is being controlled by only one instance domination would mean that another could be placed on it (or maybe even a third one).