In the scenario you’ve described, if Thanos possessed all six Infinity Stones and evolved to possess Ultra Instinct, it would indeed be an incredibly dire situation for the Avengers and other superheroes. Let’s explore the potential consequences:

Avengers’ Defeat: With Thanos wielding the Infinity Stones and possessing Ultra Instinct, the Avengers would likely be completely overwhelmed and defeated. Their combined strength, skills, and tactical abilities would be rendered ineffective against the immense power and near-unbeatable reflexes of Thanos.

Destruction of the Universe: Thanos, with his newfound powers, could potentially use the Infinity Stones to wipe out not just half of all life as he initially intended, but the entire universe itself. He could reshape reality, erase entire civilizations, and bring about untold destruction on a cosmic scale.

Superhero Desolation: The defeat of the Avengers would have a devastating impact on        the superhero community as a whole. Without their most prominent and powerful defenders, other heroes would be left to face the chaos and destruction unleashed by Thanos alone. They would struggle to unite and mount a coordinated resistance against such an overwhelmingly powerful adversary.

Existential Threat: Thanos, having evolved to possess Ultra Instinct, would become a near-unstoppable force. He would transcend mortal limitations and become an existential threat to all life in the universe. His power, combined with the Stones, would make him an omnipotent and omniscient being capable of wreaking havoc and reshaping reality as he pleased.

Cosmic Entity: In this scenario, it’s possible that Thanos would ascend to the level of a cosmic entity. With his mastery of the Infinity Stones and Ultra Instinct, he would become an immensely powerful being, perhaps rivaling or surpassing the likes of Galactus or the Living Tribunal in terms of power and influence. He would be virtually unstoppable and could reshape the universe to his own desires.

In summary, if Thanos evolved to possess Ultra Instinct and wielded all six Infinity Stones, the consequences would be catastrophic. The Avengers would be defeated, other superheroes would suffer greatly, and Thanos would become an unimaginably powerful and destructive cosmic entity, posing a threat to all life in the universe.