Magnus

Lord Magnus was a powerful Dominarian druid and the avatar of the woods on southern Argenti. His physical body was old and weathered, and he resided within the Sylvan Library, from which he could control the growth of all plant life and command all the wildlife in the forest.

History
He allied with Lady Caleria in her rebellion against the Empire of Madara. When the kentsu attacked Argenti, Ayesha Tanaka took him from the Sylvan Library. He apparently died, but his body disappeared a few minutes afterwards, and when Ayesha tried to use the Library to cure herself and her student Kei Takahashi the forest itself, represented by the voice of Lord Magnus, overwhelmed her. Ayesha was forced to help end the kentsu invasion in exchange for her cure. After she defeated the kentsu and received her cure, the forest (through Magnus) told her to leave immediately, and Magnus once again took his place in the seat of the Sylvan Library. Magnus then joined Caleria once more, this time to exact reparations from Madara.

Prerevisionist
In prerevisionist continuity this character was known as Lord Magnus of Llanowar, and was the Maro-Sorcerer of Llanowar. In revisionist continuity that position has been filled by Molimo and Magnus is simply a powerful druid.