What If...? X-Men #1
WHAT IF...CASSANDRA NOVA KILLED PROFESSOR X? In a world where Cassandra Nova killed Charles Xavier in the womb, telepaths are hunted and experimented on - and what she's making from them is far worse than what she's taking. But when telepaths Jean Grey and Emma Frost escape, Cassandra Nova will stop at nothing to bring them back! Bring on Cassandra's X-Men!