Gallantmon Crimson Mode

Gallantmon Crimson Mode is a fictional character in the Digimon series. He is the advanced form of Gallantmon, remaining in that form for a limited time. While in this form, The Digital Hazard in Gallantmon's Digiciore is completely sealed so he can fight with his full power. He is known as Dukemon Crimson Mode in the Japanese version.

Digimon Tamers
Gallantmon Crimson Mode first appears in the end of episode 49 of the Digimon Tamers TV-series. Gallantmon assumed the form by asborbing the data of Grani. He appeared because Gallantmon needed to change his mode but he needed power for that. He found that power in Grani.

Runaway Digimon Express
In the movies Gallantmon Crimson Mode appears when Gallantmon and the other Mega Digimon fight against the Parasimon and when it appears that they will be defeated Takato (who has merged with Guilmon) refuses to give up. This causes a mode change in Gallantmon and the now more powerful Digimon destroyed all the Parasimon by sealing up the hole that they came through.