It has returned … once again.  
I am impressed by Sombra because he is proving to be a really powerful enemy, I think he is the only villain that the power of the elements of harmony hasn’t been able to completely defeat.  
This proves that the power of harmony is not infallible and that there may be other powerful enemies out there that could cause serious problems for our pony friends…

Have to admit: Sombra is a one stubborn stallion. He just won’t play nice with others and stay dead.

@Background Pony #CF57  
Just search for it or buy it like a man.

Sombra is the MLP’s answer to Voldemort from Harry Potter - it is simply not possible to kill him, and from S9 we have seen that when the rainbow magic hit him, he went into disintegration into ash / smoke that was immediately spread out. When the crystal heart destroyed him, it was only the horn left - to which his essence was attached. So the key to Sombra’s immortality is not only related to his essence which will not fade away when the body is destroyed just as with Voldemort - but also that as long as there is a physical remnant - even ash - is intact, he can return.
 
So even if the Transformers and the Mane 6 managed to destroy Sombra, it is not possible to kill him as long as his essence remains “alive” as with Voldemort who was impossible to kill as long as there were intact Horcruxes. Harry Potter had to destroy everyone including the scar on himself for Voldemort to die. After my head canon, if “Siege of Crystal Empire” were to become canon with S9 - it is possible that Discord pulled the evil personality from the shadow realm to which he and the umbrum were banished by the crystal heart. That can explain so much, including why Sombra was so frighteningly effective in S9 until Twilight showed him where the beer stands.
 
Sombra just can not die. First for the hoovers on Celestia and Luna (many hope it was Nightmare Moon). Then burst into pieces of the crystal heart. Since almost obliterated and expelled by the crystal heart (“Siege”). Then hit with the more fatal rainbow magic of the past in the Mane 6. Do not think full atomization or being in a different dimension will prevent Sombra from returning after a fifth death in Cybertron. Perhaps the only thing that can kill Sombra is to reunite him with the “good” Sombra (if he is canon) to have true balance, yin for yang, so he can disappear for good.
 
But in the meantime, the Transformers are in trouble. Sombra can learn about Primus through his new slaves and realize that a buried god with unlimited power lies beneath his hoovers. He will never pass up the opportunity if the story continues.

twilight no impossble your supped to be dead

Ahhhh my second favorite baddie (with Tirek being the first) is back yet again in the comics. Heeeere we go! xDD

Well, just Rainnuke him again!

@Lurks-no-More  
“Luster, I entrust you with this artifact, crafted specifically to not only defeat Sombra, but seal him for eternity.”  
“Princess Twilight, this is a dustbuster.”  
“I didn’t say it was an ancient artifact.”

“that pony sure doesn’t want to die” lmao

@GaryFisherSr  
The comic does not care about continuity

@Terminal Red  
Maybe it’s the Sombra in season 9 or the one made a cameo in Nightmare Knights.

Which Sombra? That Season 9 one?

Sombra is the closest thing to a lich we’ve seen in MLP:FiM. Getting rid of him for good is probably a job for Luster Dawn and/or her students.

Good enough explanation for me.
 
@Terminal Red
 
Sombra’s Fiendship is still compatible. So yeah she can still be there.

@Background Pony #BD27  
It’s probably still partially smoke.

Anypony noticed that Sombra’s cape is now black instead of red?

@Terminal Red  
This is a crossover. It will likely be ignored in turn by both franchises.

So Radiant hope is non-canon now? Perhaps they’ll try and fit that story in somehow. A dream Sombra had while he was reforming? Perhaps this is Sombras evil side manifested while his good side is still traveling with radiant hope?
 
Nah, that story probably completely scrapped. It’s a shame the comic has to ignore part of its own continuity.

Eeyup, it’s season 9 Sombra.

We are in serious trouble 😬