The G10 final boss, the G11 Climax Boss, the G12 final boss... basically any mission where you are permanently in Demigod mode.
The RP mission where you get to play as Goddess Morrighan for a brief time. Even more so thanks to the preceding cutscene, where Morrighan reveals her Glowing Eyes of Doom and proves just why she's a Goddess of War.
In G2 when the player encounters Esras at the end of the final dungeon. Esras summons Tabhartas, a Ceo Island Golem mixed with melted gold, who then procedes to completely demolish the player and Redire, along with breaking the latter's leg. As Esras commands for Tabhartas to finish him off, the player stops Tabhartas BY THEMSELF. And then to make the moment even more awesome, the player unlocks the power of a true Paladin and transforms right there and proceeds to defeat Tabhartas easily.