Dan Jurgens' run on Thor was already ongoing when I began reading the series. I began with issue #32 - which I bought because of the value it was giving, labeled as 100-Page Monster - with some good reprinted issues.
The beginning of the series, by Dan Jurgens and John Romita Jr, the title was starting over fresh after Heroes Reborn. A new mortal identity was decided upon - to try and realign Thor to how he was when he first appeared by Jack Kirby. Don Blake was erased by Odin, so a new more youthful, and hopefully relatable, ambulance driver Jake Olsen is introduced. Why does Thor take this identity? I've never read the issues - but Thor was merged with the identity of Jake Olsen, who died during a battle Thor was engaged in. Thor was near death as well - but was saved by being merged with Jake Olsen. Long story short: Jake is deceased - but Thor sort of takes his place and lives his life.
Jurgens work on Thor took readers in a few different directions. I only heard about this after the fact - but apparently when Jurgens wrote the newly revitalized Thor - he promised there would be new villains. During his first 25 or so issues, with John Romita Jr's fantastic art style, he introduced a new and menacing race - known as the Dark Gods.
They where fearsome and powerful creatures - who had taken over Asgard and imprisoned Odin. It's not until a year into the series that Thor is able to fight and free his people.
In the Thor Annual a new menace named Desak was introduced -- he was a villain given great powers by a mysterious goddess. Desak, Destroyer of Gods, is intent on tearing down and killing all demi-gods in the universe; he having been deeply wronged by his own former deities. Thor was eventually able to convince Desak that not all gods are bad - which gives Thor a reprieve from Desak's judgement, but is told that Desak will be watching.
After that, though, Jurgens relied on classic Thor villains for a very long time. I think this disappointed some fans who wanted to see newer stuff -- something that Jurgens would do in spades, not with new villains, but with a radical change in the status quo. That comes later, though.
For me, the reuse of all these wonderful classic villains proved quite informative for a new fan like myself. Some of the stories, though, like with the return Malekith - and the Cask of Ancient Winters - I would later find to be too derivative of the original story Simonson did.
There was a great new element added to the series - though; that of Thor Girl! What on the surface seems like a derivative gender-bending twist - I eventually found out had deep and significant meaning for the series going forward. I never read the issues where she was introduced -- but I got the essential gist of it: this entity, called Tarene, The Designate, is destined to one day elevate species to a higher level of greatness. I don't know how it happened - but Tarene gravitated towards Thor, being naive and still not ready for her eventual destiny, decides to copy Thor and try and be like him. Thus we got Thor Girl!
Andy Kubert was doing art for the series during this time - and ended his run is a great two-part story in issues #24 and 25. Thor faced the alien being (and Superman-ripoff) Gladiator! I knew Gladiator from his appearance in the X-Men TV show, as the body guard to the Shi'ar Princess Lilandra. Why is he fighting Thor? Well - this isn't the same Gladiator -- but an older version; brought from the future by Zarrko the Tomorrow Man.
It was an incredible fight! All the while, the reasoning behind Gladiators attack is less than clear. He declares that Earth's future is doomed by Thor! His trip through time, ultimately, fails - with Gladiator returning to his future time-line with Zarrko. Gladiator had failed -- and it's shown in a single shot what he was trying to prevent; that of a ruined and mired world, with people suffering - with a magnificent statue of Thor adorning the landscape. The future Zarrko is trying to prevent is still happening.
During a scheme perpetrated by Loki - Thor is severely injured in battle with the Destroyer. Jane Foster is able to heal Jake Olsen, but cannot do the same for Thor. To help expedite the healing process for Thor, Odin separates Jake Olsen from Thor. While Olsen is still deceased - he remains an independent person, similar to Don Blake. (Real, but not real.) Thor and Olsen, though, never get a chance to be merged together again.
Old villains are brought back - even ones you wouldn't initially expect. Remember how Skurge the Executioner died heroically in Hel during Walt Simonson's run? Well - he returns, much to the confusion of the Enchantress.
At the time - Marvel announced that someone very prominent, described as being powerful and rich, would die in an upcoming month. That date came and went - with the revelation of who they meant still not being understood, as the death took place at the end of an issue, with the usual expectation that - next issue - it would be revealed how this person really survived. (It's a cliche in comics, really! Not necessarily a bad one, if done correctly. Here is was simply blundered, as the character's death was unclear to everyone.) Who died? Odin died! Yes, he had somewhat died during Simonson's run - but this time is was for real. Like before, Odin had taken Surtur down with him.
A time of transition begins to take place. Thor Girl, who was injured during the battle with Surtur, had lost her ability to become the Designate. She was now trapped in her naive hero-emulating form as Thor Girl. As Thor, slowly but surely, began to take true command of the throne of Asgard - Thor Girl was able to act as Midgard's protector in his absence. Thor is resistant of his new role -- it's a position he had declined once before when Odin was last time lost. This time - though - the Odin force was beginning to grow in him.
Skurge was one of Thor Girl's first foes as protector of Midgard. Something was amiss, though. Skurge, who had died so heroically before, was now on a wild rampage - demanding to face Thor himself. Thor eventually comes down to Earth and confronts the menace. Thor realizes that this isn't the Executioner; it may be his weapon, his powerful battle ax, that is real - but this person was not actually Skurge. Transporting into Hela's domain - Thor confronts the person behind this outrage. Using his growing power, Thor reveals the deception - a creature of Hela's had been designed to take Skurge's appearance; using the real Skurge's battle ax to bolster the claim. Thor kept the ax, and foiled Hela's plot to try and obtain his soul. Afterwords Hela knows she had made a mistake, and had risked too much, as the Thor ruining her plans was an indication that he would soon command the full Odin force.
I'll end this post here - as the next phase of Dan Jurgens' epic run on Thor deserves it's own examination. After this point, everything about Thor changes - for Thor is now Lord of Asgard!