Warlock and the Infinity Watch #25

In "Raid on Asgard," Thanos and the heroes land on Bifrost and defeat Heimdall. Sensing the assault, Odin releases Asgard's warriors, believing Thor, who is imprisoned, might be used as leverage. The heroes, however, gain the upper hand, prompting Odin to join the fray. Thanos confronts Odin in a fierce duel, matching him blow for blow. However, Thanos is eventually overpowered. Just as Odin is about to deal a fatal blow, Sif and Bill intervene, revealing the truth of Thor's insanity. They realize Thor's condition isn't due to Warrior's Madness but stems from Odin's previous tampering with Thor's essence. Attempts to heal Thor fail, and with Thor wielding the power gem and threatening destruction, Odin resolves to end his son's life.