The Tantra of Siddhaikavira
The Tantra of Siddhaikavīra (Skt. Siddhaikavīratantram; Tib. དཔའ་བོ་གཅིག་པུ་གྲུབ་པའི་རྒྱུད་, pawo chikpu drubpé gyü, Wyl. dpa' bo gcig pu grub pa'i rgyud) is found in the Kriya Tantra section of the Tibetan Kangyur (Toh 544).
This tantra focuses on ritual and magic, and is arguably the first to introduce the deity Siddhaikavira—a white, two-armed form of Mañjushri—into the Buddhist pantheon. It is primarily structured around fifty-five mantras, which are collectively introduced by a statement promising all mundane and supramundane attainments, including the ten bodhisattva levels, to a devotee who employs the Siddhaikavīra mantras.