Given that Luke Cage had steel-hard skin and became crime-fighting partners with Danny Rand, the following letter from Power Man & Iron Fist #88 seemed inevitable.
A battle I would love to see is Power Man and Iron Fist against Magneto. Since Luke's skin must have indeed taken on the properties of steel and Danny's "iron fist" may have taken on the properties of iron, both would be susceptible to Magneto's mutant ability.
By the way, Power Man must be a good teacher. He taught Danny to drive in only two days.
Mineola, NY 11501
Two issues later, the duo squared off against Unus the Untouchable, who had worked with the master of magnetism as a member of the Brotherhood of Evil Mutants. Unus first appeared in X-Men #8.