A Magerobe is classed as armour. Kensai can't wear armour. Kensai/Mage can't wear Magerobe. I have spoken
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The last arrow of Legolas kindled in the air as it flew,
and plunged burning into the heart of a great wolf-chieftain.
All the others fled. -J.R.R. Tolkien, The Lord of the Rings