SaGa 3/YMMV

Crowning Music of Awesome: Both the Talon's theme and the Palace theme (also used in Pureland).
Inferred Holocaust: The Floating Continent and Pureland have sizable civilian populations. Both areas are eventually blown up by the heroes and their allies.
Nightmare Fuel: Any of the Entity's Elite Mooks and Xagor
That One Boss: Chaos and Agron. Chaos because he has a One Hit KO (Stone) and starts off with an earthquake move, and Agron because you had gotten quite used to having a fifth party member - and Agron starts off with a powerful move.