Can Bane destroy Vader's fortress?
Quotes courtesy of Deronn_solo.
First, Bane needs to rebuild the fortress:
Luke had not gone far when he stopped and looked up at the top of the cliff for a long moment, then out at the twin spires of rock. Dropping his chin to his chest and closing his eyes, he turned through two full circles, then looked back up at the cliff edge. “Yes,” he said, the wind stealing the word from his lips. “Yes, it is here.”
He sat down on the sand, cross-legged and straight-backed, and brought his hands together in his lap, fingertip to fingertip. Concentrating on a picture in his mind, Luke dipped his awareness deeply into the flow of the Force beneath him. With eyes that looked inward, he found what he was seeking, like flaws in a near-perfect crystal. He extended his will.
The sand around him stirred. The rocks shuddered, shifted, then began to rise from the sea and the sand as though sifted from them by an invisible screen. Swirling through the air as they sought their place, the stones took shape as broken wall and shattered foundation, as arch and gate and dome—the ruins of Darth Vader’s fortress retreat. It hung in the air around and above Luke as it had once stood atop the cliff, a dark-faced and forbidding edifice.
There was no record in Imperial City’s files to say whether his father had ever occupied the fortress, though it had clearly been built for him in accord with his instructions. It had been empty when it was destroyed by a B-wing’s blasters, in the days after the New Republic reclaimed Coruscant. Was this where Vader plotted his conquests in the Emperor’s service? Was this where he had come to rejuvenate after a battle? Had there been celebrations here, self-indulgent pleasures or cruelties? Luke listened for the echoes of the old evils, and could not be certain. But that did not matter to his plans. As he had redeemed and reclaimed his father, he would redeem and reclaim his father’s house.
Now the stones swirled again in the air, joined by others plucked from the sea and stripped from the face of the cliff. Now broken edge fused against broken edge, and the dark faces of the rock lightened as their mineral structure was reshuffled. Now heavy rock walls and floors thinned to an airy elegance as if they were clay in a potter’s press. Now a tower stretched skyward until it rose above the edge of the cliff.
When it was done, the last gap closed, the last rock transformed, the structure securely perched just above the sand on pillars of stone extending down to bedrock, Luke brought the E-wing down the beach and nestled it in the chamber he had made for it. It was not a door that closed over the opening, though, but a solid wall that closed out not only the wind and the cold, but the world. “Shut down all systems,” Luke told R7-T1. “Then place yourself in standby mode, I won’t be needing you for a while.”
The last task was to inspect his retreat from the perspective of any outsiders whose gaze might fall upon it. All was as he had planned. From the sky, it appeared as part of the beach. From the sea, as part of the cliffs. From the beach, as part of the sky. From the cliffs, as part of the sea. It was not a trick of camouflage, but a simple matter of allowing the essences of its substance to be seen. The retreat was of the sea, and the rock, and the sand, and the sky, in harmony with them rather than imposed on them.
The last test was to climb the tower and inspect the view. But when he looked to the east, he found his view blocked by the lowering clouds. So he waited, shrugging off time as easily as he shrugged off the cold. He waited until the wind finally blew the storm away, until he could see the snow-capped Manarai Mountains ruling over the jewel of the Core, outlined against the sky by the light from the yellow-faced inner moon.
He needs to do it in the same implied timeframe. Note that the fortress is high enough to scrape the skies and to have a hanger that can hold starfighters.
Then, Bane must destroy it:
A damp, cold wind blowing out of a broken sky buffeted Luke Skywalker as he stood on the cliff above his seacost hermitage. He stood there a long time, thinking off all the reasons he had raised it from the rocky sands, of the work he had thought to do there. He had taken the broken pieces of his father’s fortress retreat and tried to remake them into something that could redeem them from their history. But he saw now that all he had managed to build was a prison, and that he had been fortunate to escape it.
Extending his hands and his will, Luke found the points of greatest stress within the structure and pressed upon them, found the points of greatest fragility and sundered them. With a roar that momentarily rivaled the wind, the hermitage collapsed in on itself, crushing the fighter still sealed within it.
But that was not enough to satisfy Luke, not enough to forever erase the temptation. One after another, he raised the pieces of the ruined hermitage, the broken ship, up out of the sand and into the air, crumbling them with the force of his thoughts, until it was a dense, swirling cloud of pebble-sized fragments and metal bits. Then, with a final, explosive effort of will, he hurled the cloud of debris far out beyond the breakers, where it rained down on the churning water and vanished from sight.
Note that he must lift all of it up and then blast it away with a single exertion of telekinesis.
He does not get a nexus.
If he can't do it, give him Kas'im and Sirak for help.