New Mutants #21 Marvel 1984 Vol. 1

First time Illyana Rasputin is referred to as Magik, in a character bio
'Magik' only used in the title of the previously published miniseries 'Magik: Storm and Illyana'
Dani Moonstar becomes Mirage
Doug Ramsey joins The New Mutants
1st full appearance and origin of Warlock