Legion brought a lot of lore involving the Vrykul and titans. Most prevalent is no doubt Odynn and everything around him. A lot of Legion gives off the vibe that some folks at blizzard are really into Odyn and the Vrykul as well as the stuff they bring to the table. However Odyn's backstory is kind of dickish. Ultimately he whined that he didn't get his way when some dragons showed up the keepers and their creation, so went and learned shadow magic (necromancy) and enslaved someone he considered a daughter to his will forcibly, as well as numerous other women (he later does this again in the warrior questline, finding it funny to bind someone to his service forcibly).
In game he's always cheerful and boisterous. He is in many ways the gleeful warrior trope. Though it's been an annoyance to many that he just keeps on testing you despite every time saying you've proven yourself. This is especially bad for warriors who go through half a dozen tests despite from the get go (and more coming). Then you have his myriad titles and deeds. He was the greatest keeper, the "prime designate", he's somehow Thorim's father according to warrior questing and the god of storms according to monk questing. This veneration continues in 7.2 where Eitrigg and Crowley are overjoyed to be working with Odyn's champion to the point that they join Odyn's army. He appears in disguise and guides you along as a fun character with a popular voice actor then reveals who he truly is in what was likely meant to be a surprise twist that shifted love from Havi to Odyn.
But of course they never mention his terrible history in all this. There is never much done to flesh him out, he is here, he's Odyn, what more do you need? Warriors as a whole did not get a warrior order hall or warrior questline by blizzards own admission: they were so hyped on Odyn that the class instead got a Vrykul storyline, despite it being pointed out that Odyn lets a lot more than just warriors into his hall. Hell, almost all the females are simply aspiring paladins.
It all just makes me wonder if blizzard expected players to love Odyn. Its clear blizzard does, but from my own experience I've seen little else but annoyance at him.