Angel of ULTIMATE DESPAIR! How do you beat it?!

[Vulnona]

Hiya!
So I am playing V13 and in Chapter 13, you fight

Spoiler

Rift Guardevoir, the Angel of Death.

Now, in V12, this seems to have been a fight against a couple of Ralts and Kirlia as well... but in V13, it's now only Guardevoir herself.

The only problem is: She has four shields up and an incredibly wide HP bar!

• Perish song and Destiny Bond do not work, and neither does Curse (it says that it afflicts Guardevoir every turn, but it never actually depletes her health)
• Multi-hit moves like Tail Slap only hit once on a shield, and each shield seems to need a certain amount of damage to break (I usually need two hits for one shield)
• Misty Terrain does not work - my Pokémon still go to sleep
• Memento only lowers her attack stats, not her special attack stats - which SUCKS!
• Thunder Wave does not work (though Nuzzle does)
• PP stalling might not work, as Guardevoir's Hyperspace Hole sems to have UNLIMITED PP!
• Lowering her accuracy won't work because of Hyperspace Hole either

Guardevoir either one-shots every Pokémon I have or lulls them to sleep with incredible accuracy.

She is carrying a Lum berry, which means the first paralysis/sleep/burn/etc. is cured instantly.

Now, I could still try a couple of other strategies... were it not that I am stuck in the past without access to anything outside of Hiroshi City!

My Insomnia Hypno is of no use against Guardevoir, and my Vital Spirit Lycanroc is just not useful enough (it no longer has Accelerock, and I have no way to teach it here).

The Steenee and Ribombee you can catch in Hiyoshi City are useless so far, especially since I cannot evolve Steenee without an attack re-learner. I will try to do something with Sturdy Steelix, but so far...

I am at my wit's end here.

How the fluff do you beat this thing?!

 

 

EDIT: Okay, so I finally beat her. I used this strategy:

Spoiler

1. A Pokémon with Sturdy and Flash. I used a LV 5 Carbink and got in two Flashs. Lucky me!
2. Once Guardevoir's accuracy is down that much, her AI compels her to only use Hyperspace Hole anymore, since it is a move that always hits. So this is when you can either use a very tanky mon (my A-Ninetales, Sylveon and Medicham can take one hit of Hyperspace Hole without dying) or - I did not try this yet - a Dark type which will be immune to Hyperspace Hole. Crush her shields one by one and revive when necessary. (I used A-Ninetales with Blizzard and froze over the dimension, so that buffed ice moves. Sylveon with Pixilated Hyper Voice worked nicely, too, since that is unaffected by the Dimensional Rift field.)
3. Once her shields were down, it went down quickly. She can now be hit by hail, curse, burn, whatever and whittled down slowly. I found that just attacking her again and again worked nicely.

 

Edited July 19, 2021 by Vulnona