| Barbarosa is my enemy. That... is all.
Kreutz was a warrior who served under Geil Rugner during the War of Succession. Loyal to Geil, Kreutz was considered the only truly great leader in his oppressive government. Following the death of Geil and the ascension of Barbarosa Rugner to the throne, Kreutz made his way to Dragon Knight's Domain and secluded himself. Even years later, he still considered Geil to be his only master.
In retrospect, I would have voted for Geil, yes.
There, during the height of the Gate Rune War, his former rival from the War of Succession, Humphrey Mintz, invited him to join the Toran Liberation Army, considering him Geil Rugner's greatest general. Kreutz accepted this offer only for the chance to kill Barbarosa and avenge his master. He held little interest in the struggles of the Toran Liberation Army itself.
Still, Kreutz was a powerful ally in battle, wielding an oversized, two-handed sword in battle. Kreutz's strength with the weapon was such that he could crush bones with the power behind his swing, instead of merely killing foes quickly.
Following the defeat of Barbarosa and the fall of the Scarlet Moon Empire, Kreutz simply left the country, his vengeance secured, refusing attempts to bring him into the Republican Army.