Harry Potter

Limitations and Cost (to maintain the balance of the world): *

• Fading: *Each change to reality requires a colossal cost. For every fateful event rewritten, an angel pays with their own memories. Saving a person's life means forgetting the taste of food forever; preventing a war means losing knowledge of one language; undoing Voldemort's fall means losing their own name. Sooner or later, such an angel risks turning into a pure chronal golem without a personality.
• Canonical Inertia: *The magic of the world itself resists global change. You can't save Cedric Diggory or Harry's parents with a simple snap of your fingers—the fabric of reality will try to "mend" the hole, creating even more terrible tragedies in its place (the butterfly effect). Therefore, the angel only intervenes when the very existence of the timeline is threatened.
• Death Reversal: *If the High Angel is killed, all changes they made to that particular timeline will be undone by reality within minutes. The world will return to its original state with a terrible grinding sound, and the survivors will experience a monstrous attack of déjà vu.
• Horcrux Inviolability: Because Tom Riddle's soul is inextricably bound to multiple points in time through soul shards, directly removing him from history is impossible—the angel can only isolate his physical shells, but his essence itself will remain a blight on the tapestry of time.

External manifestations in the setting: *

• When an angel uses power, clocks throughout the area begin to tick backwards, and the hourglass of prophecies in the Department of Mysteries turns over on its own.
  *Spells aimed at him are caught in a "loop": the Patronus beam or Stupefy returns to the sender an instant before it was fired, forcing the attacker to involuntarily defend themselves against their own spell.
• Elderly people near him may suddenly smell their school uniforms as their personal timeline is locally reverted

Mechanics of action: *
1.* Thread Reading (Divination of Absolute Accuracy): The angel is able to see the past, present, and the most probable future simultaneously without using a wand. He doesn't need a Pensieve—he literally reads the residual magic of events ( Residue Magica ) out of thin air. In the context of Rowling's setting, it seems as if, for him, Dementors exist eternally in one point, and ghosts are just pale threads of cut-off lives.
2. Fate Splicing: Where an ordinary wizard alters memory (Obliviate), an angel can alter the action itself. He finds the necessary thread of the past and carefully weaves a new trajectory into it. In this case, reality is rebuilt instantly and painlessly for the universe. Paradoxes are impossible here: the angel sees in advance which knot in the tapestry the new thread will lead to. For example, he can ensure that Neville's parents were never tortured, and the world will change as if that were the original order of things.
3. Echo Effect (Magical Retrospection): Any spell leaves a trace. The Angel can make magic "forget" that it was cast. To everyone around, an Unforgivable Curse cast a second ago will simply disappear, and the wizard's wand will remain dry, because the blast physically never left it. This is the perfect counter-curse against any magic, including Avada Kedavra.
4. Stasis of the True Moment: The Angel can remove a tiny section of space-time (such as a falling person or an exploding sphere) from the general flow and suspend it in a personal pocket outside of time. Inside this sphere, no external magic operates, there is no aging or decay of matter.