In Howl's Moving Castle
, Wizard Suliman is the Royal Wizard of Ingary who is defeated by the Witch of the Waste
. Prince Justin
is a close friend of his.
Like Wizard Howl, Wizard Suliman was one of Mrs. Pentstemmon's pupils. Also like Howl, he comes from Wales and uses a variant of his real name, which is Benjamin Sullivan.
He is described as a strong-willed man, tall and red-haired, with craggy features.
See also Howl's Moving Castle (spoilers).