D'Artagnyan is a female demihume feline musketeer from the Monster Strike universe. A trip to Tokyo leads her to witness Lucifer singing in a moonlit park, an encounter causing persistent heart-throbbing sensations. This later intertwines with attending an Angely Diva concert, where she resolves to pursue her own dream of becoming an idol, marking the start of her journey focused on song and personal growth.

Her background features multiple evolutionary stages. Initially a 5★ Balanced-type unit with Bounce sling, she possesses Mine Sweeper and wields a Big Bomb bump combo. Evolution yields "Feline Musketeer D'Artagnyan," a 6★ unit gaining Null Warp gauge and upgraded attacks like the Castelmore Cannon targeted laser followed by homing shots. Ascension transforms her into "D'Artagnyan the Pawblaster," shifting to Pierce sling type with Null Damage Wall gauge, Follow Up Piercer bump combo, and the Bastille healing wall Strike Shot. Seasonal variants like "Santa Marshal D'Artagnyan" offer thematic adaptations.

Transcension brings forms like "Proud French King D'Artagnyan," introducing enhanced abilities: Mine Sweeper L, Super Laser Stop, and SS Turn Charge. Her bump combo becomes Follow Up Tri-Piercer, and her Strike Shot creates healing walls on all contacted surfaces. The pinnacle is her Transcension: Kai state, "French King D'Artagnyan Harboring the Three Musketeers' Feelings," classified as Super Balanced. This form incorporates Dash gauge, Connect Skills requiring specific party compositions, Sharp Angle Follow Up Tri-Piercer, and Power Drive sub-bumps. A corresponding Santa-themed Kai variant exists.

Her design and abilities consistently blend musketeer motifs with feline traits, each transformation emphasizing increased combat versatility through new skills and synergies.