Avengers Arena 1A

1st appearance of Death Locket aka Rebecca Ryker, a teenage version of Deathlok
1st appearance of Kid Briton, an alternate reality version of Captain Briton
1st appearance of Cullen Bloodstone, brother of Elsa
1st appearance of Anachronism, a boy whose soul had been merged with the spirit of a Celtic warlord
1st appearance of Nara, an Atlantean
1st appearance of Apex, a bio-engineered superhuman
Death of Mettle