Richelieu serves under the Royal Mother. He presents to her a source describing the location of the Blue Eye of Gaia in The French Conniption, which leads to her forming an alliance with the Spectral Space Pirates (Sheer had been listening in) to find it.
Richelieu is sent alongside each of the Space Pirates in turn to each subsequent suspected location for the Blue Eye of Gaia: an old orphanage in The French Conniption, the Chateau du Duke Dumas in The Wee Musketeers, both of which were dead ends, and finally Vasasi Castle in All For One and The Haunted Hunt.
He eventually corners the D-Team and reaches to grab the Blue Eye of Gaia, before King Louis arrives and orders him off, giving the Cosmos Stone to the D-Team.
He is shown to be very ruthless when seeking his goals, imprisoning Princess Anne without concern, and fighting D'Artangnan one-on-one with a metal sword against a wooden stick, even resorting to pulling out a pistol when he became outnumbered and outmatched after the other Teen Musketeers joined the fight. However, he shows complete, if reluctant, loyalty to his rightful authority, immediately stopping when King Louis, though a child, began directly giving him orders contrary to the Royal Mother's previous instructions.
|p · e · t||Secondary Characters|
|Season 1 Allies:||Aki Taylor · Dr. Owen · Dr. Drake · Mrs. Drake · Newswoman · Monaco Fisherman · Dewey · Michelle · Amy · Mr. Stanley · John · Mary · Patrick · Temple Priest · Captain Mackerel · Meena · Stanley Spinoberg · Shino · Jonathan · Dr. Ancient · Dr. Cretacia|
|Season 1 Enemies:||Doppelgänger Alpha Gang · Ungaro|
|Season 2 Allies:||Sophia · Spartacus · Jim · Sanzo Hoshi · Shogun Tokugawa · Hanzo · Zahrah · Aladdin · Sultan · D'Artangnan · Athos · Porthos · Aramis · Princess Anne · Lady Constance · King Louis · Duke Dumas|
|Season 2 Enemies:||Sulla · Blackbeard · Copper · Kunoichi · Takeda · Zayid · Jon-Jon · Rasheed · Chancellor Richelieu · Royal Mother · Giant Insects|