Who would use a Pokemon with 1 HP?

Well, Shedinja isn't meant to be a joke, but it is fairly gimmicky. The lack of bulk is meant to balance its ability, Wonder Guard, and speaks to its origins. It is meant to be a shed exoskeleton, after all, which in reality are very thin and fragile.

I do know that GofD, here in the forums, apparently built a successful team around one in Ubers, and there are a few methods that I've seen that allow it to achieve a level of invulnerability to the point that only recoil damage and opponents with Mold Breaker can take it out if it's allowed to set up. It's not horrible, and it's not terribly great either, but it can be fun to use if it's used correctly.

Shedinja is a very gimmicky Pokemon that requires a lot of support. When given the right support, and if you make your moves right, Shedinja can and will SWEEP EVERYTHING. I did find a lot of people I went up against with my shedinja team, had no sweet clue as to what was happening.

Shedinja is only a Joke, until you realize what it is capable of.

There's also an elaborate combo you can pull off in Triples where you can get a mostly invincible one that only dies to Leech Seed or being phased out. It involves giving it Sturdy and paralyzing it while it holds a Safety Goggles.

I looked for reference video to give as an example. The first one I found set the Shedinja up properly, but then it died after making its first attack because of a Rocky Helmet. It was quite sad...

Commonly Doubles strategies revolving around Shedinja involve giving it Sturdy in some way, via a combination of Skill Swap and Entrainment. Gen 6 made it easier, removing 1 step, so Carbink can Skill Swap Sturdy onto something with Entrainment directly. This makes Shedinja unkillable via direct damage. However, more often than not, Shedinja can be killed with indirect damage. Other variant strategies involve a Ditto or Smeargle Transforming into Shedinja, that require a bit less setup. While they don't do as well as the other strategy, these do NOT die to indirect damage. (So really it's pick-your-poison.)

Is it a gimmick strategy? Yes. Are its counters not that hard to get? Yes.
Does it totally crap on any team unprepared for it? Yes.

In fact, the very first rule of Double Battles is "Make sure you can stop Shedinja. If you can't, you lose."

I've also seen giving Shedinja Entrainment through mimic, than passing wonder guard to an electric Pokemon with an air balloon. then Sub and Toxic everything.

...that reminded me that Wonder Guard auto-loses to Mold Breaker. I totally forgot about that.
...but it's still rare enough that it doesn't always come up.

Could always give it to an Elektross with gastro acid?

Here. I just made this for fun this morning.

It's not perfect, and it would have been stalled out if my opponent hadn't quit; I'm not really a triples battler in the first place. Coil-Crunch probably isn't the best way to go, anyway. Infiltrator toxic or burn will be dangerous to this set as well.

Lmao, that was fun to watch. With hope Gastro acid can be used to remove infiltrator/Mold breaker

Wow, duh! How could I forget about that? Yeah, that would work if it got there first, although it is a bit slow...

I think that Shedinja, in competitive, is a really ****...

Shedinja is great because he ability

Shedninja is an annoying pokemon to get but fun to use. What is the best nature for a shedninja? I have an adamant nature shedninja and don’t know how to use it like my O.P. Garchomp or Charizard? please help me in anyway possible. Thanks.