Triumphalism vs. Triumphalistic — What's the Difference?

Disproportionate or unreasonable celebration of the perceived successes and virtues of a given group, religion, or ideology relative to those of others.

Of, pertaining to, or exhibiting triumphalism

The attitude or belief that a particular doctrine, culture, or social system, particularly a religious or political one, is superior and that it will or should triumph over all others.