In Grip of the Shadow Plague, he attempts to rescue Maddox from the preserve Rio Branco in Brazil but fails. He is bitten by a darkened Satyr, Newel, during a fight and he turns into a shadow. He can only be seen by Seth when he in this form because Seth has dark marks left by the nail from the Revenant. Seth learns that Tanu can only talk to him when the sun is setting because when in his shadow form, Tanu is burned by the light. Once the Shadow Plague is destroyed, he returns to normal.
In Secrets of the Dragon Sanctuary, Tanu is seen more as a healer in this book. He somewhat healed Warren in the Knapsack and under Vanessa's control, he slew Glommus, a sleep-infusing Dragon, inside the Dragon Temple.
In Wrath of the Dragon King, Tanu comes to Wyrmroost to assist Kendra and Seth. He goes to the Feast of Welcome with them, using a Potion of Courage to withstand the Dragon terror. After Madrigus is killed, Tanu snatches some of the Dragons organs to make Potions with. When his Griffin Titan is killed, he, Kendra, and Seth makes their way down Skyhold on the Safe Road. He manages to get to Terrabelle with the Somber Knight and later escapes to the Zowali Protectorate. Inside of Stormguard Castle, he is turned to silver, but should be normal agains since the contest there is over.
- Energizing Potions
- Enlarer Potions
- Fire-Resistant Potion
- Gaseous-State Potions
- Potions of Emotion
- Shrinking Potion