zealous

marked by active interest and enthusiasm

Filled with, or characterized by, zeal; warmly engaged, or ardent, in behalf of an object.

Latin 'zealus' meaning zeal, fervor

“Her eyes were guilty gates, that let him in By shutting all too zealous for their sin: Each sucked a secret, and each wore a mask.”

— George Meredith, Complete Project Gutenberg Works of George Meredith

“The king attempts to eradicate the fake monks, but during this attempt, an over-zealous minister ends up killing some real monks.”