From a veteran superstar finally realizing his dream to expansion intrigue on multiple fronts to seemingly never-ending drama in Canada's capital, there were plenty of hockey talking points that endured throughout the calendar year.

While Gritty has been the talk of the NHL and beyond since the strangely lovable Philadelphia Flyers mascot was introduced in the fall, a handful of significant subplots have pervaded hockey discourse for much of the last 12 months.

Here are five of the league's biggest storylines from 2018:

5. Erik Karlsson's future

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Whether Karlsson would ultimately be traded or choose to re-sign with the Ottawa Senators was a burning question that began to simmer in 2017, but it reached a boiling point this year, and even now, his future beyond this season remains uncertain.

The all-world defenseman's name was firmly entrenched in the rumor mill at the beginning of 2018, but he remained with Ottawa through the trade deadline, insisting afterward that he never asked to be dealt.

On July 1, the first day the Senators could formally offer him a contract extension, they did just that, but the uber-talented blue-liner turned it down. The club then gave other teams permission to negotiate with him, which led to the Tampa Bay Lightning reportedly making a failed bid for him several days later.

The trade talk cooled down until late August when he denied a report that he was unwilling to sign a long-term deal in Canada. The saga culminated with the trade that sent him to the San Jose Sharks in September.

However, Karlsson's future plans are still unclear. The 28-year-old remains in the final year of his contract, and although he's looked much more comfortable recently amid what may still be an adjustment period in San Jose, there have been no firm indications from his camp of his intentions beyond the current campaign.

4. The Senators' scandals

It wasn't just Karlsson's uncertain future that regularly put Ottawa in hockey headlines in 2018. The Senators were involved in a slew of off-ice incidents this year, as a disappointing 2017-18 season on the ice preceded a disastrous spring, summer, fall, and winter away from the rink.

Then-assistant general manager Randy Lee was arrested on a harassment charge at the draft combine in late May, which led to his eventual resignation in August. An online harassment case brought forth by Karlsson's wife, Melinda, against Monika Caryk, the fiancee of Erik's then-teammate Mike Hoffman, led to Hoffman being traded one week later.

Then, in November, Ottawa players were captured in a video criticizing assistant coach Martin Raymond inside an Uber, which led to apologies, the driver being fired, and an admission from Mark Stone that the club knew about the footage before it went viral.

Later in November, the Senators and Trinity Group, the club's partner in its downtown arena proposal, revealed an internal dispute between the two parties. Then, in December, Eugene Melnyk announced through the team that his company, Capital Sports Management, was suing Trinity Group for $700 million in the wake of the failed redevelopment bid.

3. Seattle

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The fact that it was essentially a foregone conclusion didn't stop Seattle's pursuit of an NHL franchise from being a consistent topic of discussion throughout the calendar year.

If there was any doubt that there would be demand for the league's product in the Pacific Northwest, those fears were allayed in March, when the then-prospective team sold 10,000 ticket deposits within 12 minutes of making them available.

The franchise wasn't officially rubber-stamped until early December, but hockey fans and media members alike spent many months before that pondering potential names, logos, and jersey concepts.

Fans in the Emerald City won't get to see their new squad play until 2021-22, and the team has yet to establish its full identity. But much like the supporters of the league's previous expansion darlings (more on them below), the Seattle faithful have made it clear early on that they're more than ready to support an NHL team.

2. The Golden Knights

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Vegas' inaugural NHL season was unlike anything the league - and arguably professional sports - had ever seen before.

Yes, the Golden Knights officially joined the NHL in 2016 and technically began play in 2017, but they truly peaked in 2018, simultaneously captivating and shocking the hockey world by making an improbable run all the way to the Stanley Cup Final in June.

They became the most successful expansion team ever in the process, surpassing even the most generous expectations and doing so in uniquely Vegas fashion, with absurdly delightful pregame presentations, a drumline, and a makeshift castle inside T-Mobile Arena.

Sin City put its one-of-a-kind stamp on the NHL in the Golden Knights' debut campaign, and the league's 31st franchise was undoubtedly one of the best stories in hockey this year.

1. Ovi

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If this past offseason was the "Summer of Ovi," 2018 was unquestionably his year.

Alex Ovechkin silenced the critics once and for all by leading his Washington Capitals to a Stanley Cup championship for the first time in his career. That feat alone was a gargantuan story, but the Russian sniper did far more over the course of the year, accomplishing several other impressive on-ice feats and then going on a bender for the ages after hoisting Lord Stanley's mug.

He was named an All-Star for the 10th time, hit the 600-goal plateau in March, scored the all-important opening goal in Game 7 of the Eastern Conference Final against the Lightning, tallied in Game 5 of the Cup Final to help Washington win the title, captured the Conn Smythe Trophy as playoff MVP, and won the "Rocket" Richard Trophy for the seventh time.

Then, there was the partying, as he commemorated the championship by doing push-ups in a fountain with his teammates, doing a keg stand with the Cup, and generally entertaining the masses with his months-long celebration.

His offensive exploits both last season and so far in this one are all the more impressive considering he has done it in his 13th and 14th NHL seasons and is now 33 years old. Ovechkin was the biggest hockey story of 2018, and it wouldn't be surprising to see him in the 2019 conversation, as well.