There's a reason why there are two orange pads on the battlefield and one on Straga's hammerUse the Voidwalker on one of the pads and then once again at the side of Straga's hammerWhen he raises it up to pound you, quickly use the nearby portal to teleport to his back where you have to attack his "switch" on his backWhen he's down, just slash his head until he rises up again.

He'll summon enemies which you need to clear to proceed to the next bitDuring this part, shoot charged shots on both orange pads before you kill all the enemiesWhen he raises his hammer and bangs the ceiling twice, that's when you need to use the portals to leap upwards and away from his oncoming horizontal swipesUse Shadow Flight after the portal jump just to be safeTo finish him off, just keep teleporting behind him with the aforementioned tactic about two more times.

Uriel, Round Two

She still has a few of her old moves, but she now has a couple moreFirst, she will stand in a corner and summon heavenly blades that will impale youThe blades are telegraphed by the faint blue silhouette that appears on the ground before they come up, so just move quickly and dodge out of the wayShe still keels when you do combos on her, so go nuts with your weapon of choice.