Incredible Hulk#135(1971)

In the 41st century, Kang the Conqueror is furious that he still has not been able to defeat the Avengers and thereby take over the 20th century. The time lord decides to take an alternative approach to defeating the Avengers: changing history in such a way that the group is never formed. To this end, Kang decides to target the World War I hero, the Phantom Eagle, who will be the instrument of Kang's ultimate revenge. By destroying the famed hero, history would take another course that would see to it that the Avengers were never formed. However, when Kang travels back in time, his Chronosphere gets caught in a time-storm that prevents him from entering the year 1917. Forced to return to his citadel, Kang decides to find another pawn who might be able to break through the time storm. Deciding to use the Hulk as his pawn, Kang transports him from the year 1971 to his own time to obtain his aid. Although the Hulk refuses at first, Kang offers him a way of destroying Bruce Banner once and for all. Kang shows the Hulk one of the Phantom Eagle's missions where he destroyed a massive new German cannon which would have led to a German victory in the war, and tells the Hulk to prevent this from happening. The Hulk, who believes that Banner is a separate being from himself, agrees to do it, just barely comprehending that destroying the pilot will cause Banner to perish. Kang doesn't tell the Hulk that the great cannon, if not destroyed, is destined to fire a deadly barrage that will kill Banner's unmarried grandfather who fought in the war, thereby erasing Banner and the Hulk -- the key being that led to the formation of the Avengers -- from existence. The Hulk is then sent through the time stream, and his nigh-indestructible body and near-limitless strength are able to penetrate through the time storm. Since the Hulk truly hates Banner, it is presumed that this motivation elevated his rage and power to incalculable levels, allowing him to accomplish the feat upon striking the second blow. The Hulk ends up in the year 1917, right in the middle of a battle between the opposing armies. When German soldiers attack him, the Hulk easily smashes them and begins his mission by tracking down the Phantom Eagle. Operating out of a tiny hidden airfield in France, the Eagle himself is preparing his bomber run to stop the gigantic cannon from ever being used. After taking off and managing to fly almost to his target without being challenged, the Phantom Eagle and his plane are spotted by the Hulk who leaps at him. Seeing the green giant heading straight for him, the Eagle has to swerve to avoid him, but this forces him to jettison the explosive-loaded drone plane prematurely, causing it to miss its mark and explode harmlessly. The German army, witnessing this spectacle, begins firing on both the Phantom Eagle and the Hulk. This in turn infuriates the Hulk, who dives at the army and ends up destroying the giant cannon himself. With his mission a failure, the Hulk is confronted by an astonished Phantom Eagle just as the energies of the Time Storm begin sending the Hulk back to his native time. Kang tries to prevent this by using the power of his mind to keep the Hulk there. However, this fails to work and as the Hulk is transported back to the year 1971, Kang finds himself sucked into limbo where he will drift, his mind a blank white page, forever. The Hulk reappears in his own time, unconscious and reverted back into Bruce Banner.