Excalibur: Weird War III (1990) #1

The powerful Captain Britain, the shape-changing Meggan, the intangible Shadowcat, the swashbuckling Nightcrawler, the mysterious Phoenix, and Lockheed the Dragon. Forged in the fires of their tragic pasts, they have banded together to fight a modern-day crusade against the forces of evil. An age-old evil has firmly established itself in another dimension. But now, realities are crossing and the malevolent power - with the help of some well-known mutants - threatens to gain a foothold on Earth.