This article introduces an easy way to defeat Ultra Necrozma, which appears in the latter half of the story in Pokémon Ultra Sun and Ultra Moon (USUM). If you're having trouble defeating it, don't know how, or find it difficult, please use this as a reference.
Easily Beatable with Mimikyu
This introduces a strategy that utilizes Mimikyu's Ability and the TM "Toxic". Since it's a tactic to chip away HP with Poison damage, there's no need for level grinding!
| How to Get | |
|---|---|
 Mimikyu | [Ula'ula Island] Catch in the wild at Thrifty Megamart (low chance) Obtain by collecting Totem Stickers (80 stickers) |
Can Reliably Inflict Poison Status
Mimikyu's Ability [Disguise] nullifies an attack once. Since it won't be knocked out in one hit, you can use Mimikyu to inflict Poison status on Necrozma.
Ability Also Recovers with a Revive
The Ability [Disguise] is lost after taking an attack once. However, by using a Revive on a fainted Mimikyu, you can regain the effect of the Ability. Since you can stall for two turns even after reviving, you can reliably defeat it.
Table of Contents
Preparations for Defeating it with Mimikyu
Things to Prepare
- - Mimikyu (one obtained with Totem Stickers is also fine)
- - Toxic TM
- - Revive
Obtain Mimikyu
Mimikyu appears at a low rate in the Thrifty Megamart, which was also the stage for Acerola's trial. Since it's hard to encounter, it's recommended to obtain it by collecting 80 Totem Stickers in Pokémon Ultra Sun and Ultra Moon.
No Level Grinding Needed
Mimikyu won't be used for normal battling but will utilize its TM and Ability, so level grinding is unnecessary. If you don't have one, just catching it is enough.
Teach it Toxic
Use a TM to teach Mimikyu [Toxic]. The Toxic TM can be obtained in Aether Paradise at the [Dock Area B1F, bottom-left].
Prepare Revives
Purchase Revives at a Pokémon Center; having 10 should ensure you can clear it. The [Max Revive] obtained during the story also works.
Steps to Defeat it with Mimikyu
1. Inflict Poison Status on Necrozma
Place Mimikyu, which has learned Toxic, at the head of your party, and inflict Poison status with Toxic as soon as the battle begins. Thanks to Mimikyu's Ability, it can prevent damage from a move once, so even if it's slower, it can reliably inflict Poison status on Necrozma.
2. Revive Mimikyu Immediately if it Faints
If Mimikyu faints, switch to your next Pokémon, then revive Mimikyu with a Revive (or Max Revive).
3. Send Mimikyu Out Again
When the Pokémon after Mimikyu faints, send Mimikyu back into battle.
4. Can be defeated by Poison damage alone
By repeating the cycle of [Mimikyu faints → Revive with Revive (or Max Revive) → Send out Mimikyu.] a few times, you can reliably deal Poison damage to Necrozma. Necrozma's Poison status will not be cured, so just by repeating this, you can defeat Necrozma.
What is Ultra Necrozma?
Necrozma's Form that Appears in the Latter Half of the Story
Ultra Necrozma is a new form of Necrozma that appeared in Pokémon Ultra Sun and Ultra Moon (Pokémon USUM).
Stats Are Increased
Ultra Necrozma, like other [Totem Pokémon], is characterized by its increased stats. Its base stats are already high, and with further stat boosts, it becomes a very strong Pokémon.
Cannot Proceed Without Defeating it
You cannot advance the story without defeating Ultra Necrozma. Ultra Necrozma is very strong, so if you don't prepare for the battle, it's possible to be wiped out without even being able to attack.
