The Runestaff (aka The Secret of the Runestaff)

Blurb

The Runestaff is a novel by British author Michael Moorcock, and was first published in 1969 under the title The Secret of the Runestaff.
The novel is the fourth in Moorcock's four book The History of the Runestaff series, and the narrative follows on immediately from the preceding novel The Sword of the Dawn.