Shaw was depicted becoming the Black King in Classic X-Men #7, immediately following events of X-Men (1st series) #98. He was apparently killed in X-Factor (1st series) #67 by his son Shinobi, but returned in X-Force (1st series) #48.
In Uncanny X-Men Annual #2, Emma Frost claimed she killed Sebastian in order to secure Namor's assistance in the X-Men. She secretly detained Shaw in the X-Brig before wiping his mind and abandoning him in Tibet in UXM #534, as far from water as she could muster. He was located as a "new mutant" in Generation Hope #13, and the amnesiac Shaw helped Hope's X-Men team for several weeks. He vanished during Avengers vs. X-Men, and resurfaced in Uncanny X-Men (4th series) #6, back in command of his faculties.
Thanks to Mothervine, Shaw briefly gained a secondary mutation in X-Men: Blue #23-24, allowing him to absorb kinetic energy from anything and anywhere. However, the power turned inwards and started to emaciate him. He seems to have reversed the mutation since then.