Collecting missing lowlevel Vivid Pixpets is seriously a pain unless you create a new character each time you get too strong to collect them, as you kill them in one hit, and at 100% Health all Egg Potions have a success chance of 0

I would like to suggest a "Bomb" kind of Item you can use to reduce an glitched enemies HP to 1 if the difference between your Level and the enemies is past a big threshold (Like 30+ levels, if not more) so you can atleast give it a go with Egg Potions

It could be a cooking only Item too and only be given once in Adventure Mode to encourage crafting

And i would promote the Devolution Fruit for it, being very spiky, its the perfect candidate and is honestly seriously underused for only making the Reverse Evobars which honestly nobody uses

So the Bomb/Potion Recipe could be:
Potassium (x1)
Ruby Stew / Sunstone Stew (x1)
Devolution Fruit (x3)

Potassium is the only Vitamin that is not used for an Adventure Mode Item yet and Ruby Stew is only used for Special Ingredient Potion, tho Sunstone Stew could be used as well since its only used for Seed Potions

EDIT: Lore-wise it could be stated that the "Bomb" Potion seriously weakends a Glitched Pixpet with the power of devolution & bright light, since they are mainly found during Night time, it would be reasonable, it could be the creation of a Vivid Pixpet wishing to help Glitched ones to become sane again

Full support, I cannot catch a Bloomfer without it lol

It doesnt even have to be an item, it could be a rare scroll. Like how some pokemon can learn the "False Swipe" attack that does the same thing.

Either way I'm in full support. Every time i'm like "okay one nice little tap with my weaker attack should do it" and my pixpet, bless their heart, gets a crit

A false swipe type of attack would certainly be cool but it would create a situation where you can give it to one single pet and then be set for the rest of your vivid catching journey. And since I believe adventure was created with the intention of being played through with multiple pets, including using a new lower-leveled pet to catch lower-leveled vivids you missed, I feel like it'd be a bit too OP. Just my opinion though, I could be wrong.

However I'm not against a way of making it less impossible to get low-level vivids with a high-level adventurer. Not 100% sure about the best way to go about it though, other than having those low-level vivids also appear with higher levels.

Edit: just to really clarify; while I don't know Komodo's intentions for sure, I feel like you aren't really supposed to be able to use one single pet to get every single available vivid. You certainly can of you're careful with your level, but coming back with another pet to get low level vivids you can't acquire anymore with a high level adventurer seems intended and encouraged. And using a high level adventurer to acquire potions for your lower level adventurers is also a completely valid way of going about it.