It’s really sad that the villain of MCU’s Thor: Ragnarok, Hela, the Goddess of Death is just brawns and no brains. Now you must understand that the very reason why we are talking about this is that the character could have carried out her big mission which had been to actually conquer the whole Universe. She had awakened an army of dead and also led this army to the Bifrost, but Heimdall had stolen the Hofund, and this meant that the Bifrost could not actually be opened.
Hela had then decided to find Heimdall, but what she had not realised that there is no real need to do this. If you actually remember, after she had pushed the fake Infinity Gauntlet, she sees the Tesseract, and she then says, “Not Bad,” and walks away from it.
Almost a millennia ago, before the Tesseract had been hidden by Odin, it had been on Asgard as in Thor, a book of Asgardian legends shown sketches of Odin wielding the Tesseract. If Odin had actually used the Tesseract before, and Hela had actually fought with him in conquering a few parts of this Universe, then Hela is aware of all the powers the Tesseract.
Hela then takes the army and looks for Heimdall and the Resistance, so that she could use the sword and travel through the whole Universe and conquer one and also all the planets. But she really did not have to go through all this trouble when.
As we have established, the Tesseract ca now open portals to almost anywhere that the user wants. Loki had travelled to Earth and also led the Chitauri there via the Tesseract. The Mad Titan had also travelled wherever he wanted using the Tesseract, so Hela actually had to do just take the Tesseract, and she could get out of Asgard at any time. Odin had also used the Tesseract to build the Bifrost, so Hela actually could have had very her own Bifrost created.
However, Hela battles everyone, and she dies like any other villain. Hela could have actually done what Thanos did a movie later, i.e. defeat all the Avengers. Well, it was not meant to be that way. Things could have actually been so very different if Hela had used the Tesseract. We will never know whether the Mad Titan would have killed Hela, or made her one of his allies to get the Tesseract.
This is the synopsis of Thor: Ragnarok.
“Imprisoned on the other side of the universe, the mighty Thor (Chris Hemsworth) finds himself in a deadly gladiatorial contest that pits him against the Hulk (Mark Ruffalo), his former ally and fellow Avenger. Thor’s quest for survival leads him in a race against time to prevent the all-powerful Hela (Cate Blanchett) from destroying his homeworld and the Asgardian civilisation.”