what does no guard do in pokemon?

In the Pokémon games, the ability "No Guard" has the following effects:

In Battle

Guaranteed Hit: All moves used by a Pokémon with the No Guard ability, as well as moves targeted at this Pokémon, are guaranteed to hit. This means that even if the opponent uses moves like Fly, Bounce, Dive, Dig, Shadow Force, Sky Drop, or Phantom Force, which have a semi-invulnerable turn, they can still be hit by the Pokémon with No Guard. However, it should be noted that this ability only affects the accuracy and does not penetrate through Protect, Quick Guard, or Wide Guard. For example, if a Machamp has the No Guard ability, it can surely hit a Pidgeot that is using Fly.

One-Hit Knockout Moves: A Pokémon with the No Guard ability can use one-hit knockout moves without missing, which increases the lethality of such moves in battle.

Outside of Battle

Increased Encounter Rate: In some generations, if a Pokémon with the No Guard ability is placed first in the party, the wild Pokémon encounter rate will double. But this effect was removed in Generation IX. For example, in Pokémon Sword and Shield, when a Pokémon with No Guard is leading the party, players will encounter wild Pokémon more frequently in the overworld.

In the Pokémon Mystery Dungeon series, the No Guard ability causes the Pokémon to ignore both harmful and beneficial modifications to accuracy and evasiveness for both the target and itself. In Pokémon Unite, it is the ability of Honedge and Doublade, increasing the damage dealt and received by the user.