You recognize the device as a Pocket Myriad,
an enchanted gadget which can become any one
of a number of weapons or useful artefacts.
You both close for battle.
You may fight him with your sword.
Or you may cast a Spell.
If you cast a Weakness Spell, his skill level will be reduced.
If you cast a Creature Copy Spell,
an identical Black Elf with a Pocket Myriad will fight the Elf.
If you wish to cast an Illusion Spell.