An ancient post with little discussion on it. Even then, people pick out other characters from the same series.
Lets clear the air first on the very Importance of Warcraft. It is somewhat seen by detractors as a 'clone of Warhammers success' because it was taking the concept of Orcs from the rising popularity of DnD like Warhammer was that was taking them from Tolken as a villainous and 'evil' force of 'non' humans with a more tribal and Barbaric culture. Warcraft Orcs vs Humans was just another take of the Orcs as villains against the humans with the notion you could play as the Orcs for an 'evil' campaign. It wasn't the first RTS, but it was one of the more popular ones that lead to a sequel that improved upon many more mechanics and fitting more of a setting that set 'Azeroth' apart from many other worlds. Blizzard went onto their other games as RTS continued to flourish before the pinnacle of RTS for some people was made: "Warcraft III" and later "The Frozen Throne expansion" that gave 4 races to play as, an extremely memorable story spread throughout 7 campaigns and a bonus 'mini-RTS' of sorts and much more. This was also the birthplace of the DOTA genre through the 'Custom Games' people created. To understate Warcraft 3's importance to gaming today is folly (which is why Reforged screwing up so hard REALLY REALLY HURTS)
Now, lets shift from the RTS milestones to what most people will know Warcraft for:
WORLD OF WARCRAFT! The MMORPG that still stands today, although a shadow of itself, that has seen millions play all around the world and helped change gaming for better or worse. South Park had an episode about it, It had it's own physical trading card game and a Digital replacement, It had a Mega Bloks line up of toys and more. I bring up the importance of how big WoW is, mostly because there are people who will defend characters who appeared as a party character in one game over 20 years ago that Sakurai said "I thought about it once" and use it as a defense for the importance of that character getting in that a youtuber will make it is namesake and people will cry that the most he will ever get is a costume. And yet this cornerstone of pop culture shall only get a few people on it.
But why Thrall? Is it that I am secretly Chris Metzin and trying to make 'Green Jesus' even more popular despite many others having just as much importance? No/Maybe, But my argument is that Thrall is one of the most unique you can add out of anyone in the Blizzard Library without needing to get really niche. More people would probably want Arthas/Lich King due to the fact that he is the front of Warcraft III and the Expansion and also the main villain of the second Warcraft expansion, but in my eyes... He is just another Human Swordfighter. Illidan would be an interesting option, Night Elf with demonic traits who probably play similarly to Meta Knight... Sylvanas has her fanbase and is important to lore recently, but Thrall brings something else...
THRALL IS AN ORC SHAMAN WITH A WARHAMMER!
Thrall is a melee oriented magic user who doesn't cast magic but summons the power of the elementals. His weapon is a unique short range blunt weapon that makes him more like a brawler and to top it off... He is a race that isn't even in the game. We got all the humans from Anime to 'Homo Nintendus' (Or whatever Mario is), but an Orc? You would be hardpressed to find a character as popular and important as Thrall from another game that is also an Orc. You can argue Night Elves are different then Hylians as 'Elves' or what not, but you cannot deny that you would be hardpressed to find another Orc in gaming that reaches the heights as Thrall without having to go into Warcraft again.
Treading back onto the magic aspect; Shaman magic is quite varied that while the Original poster here states 'Heroes of the Storm', that moveset is basically his Warcraft 3 moveset to a degree. He can call upon Spirit Wolves to knock back enemies, He can cast a chained lightning spell at his enemies, He can cause an earthquake to topple nearby enemies. You can also take from World of Warcraft where Shamans can enhance the power of their weapons with the elements or drop totems that can have special effects. In the Goblin Starter zone, he entraps you into a cyclone so you can shoot lightning at people.
If you needed me to build him a Specials list, I can easily give you this
B: Enhancement - Change the element of your weapon to alter your Smash Attacks; Earth for more knockback, Frost to temporarily freeze, Fire to deal DoT and Electric for more damage. Akin to Shulk's Monodo Arts
B < or >: Chain Lightning - Zap a nearby foe with lightning that can chain to nearby foes, damage dropping per chained foe. Initial hit is 3, but can chain to 5 with a bit of a charge.
B ^: Ghost Wolf - Taking a page from WoW Shamans, Thrall takes on the Ghost Wolf form to leap into the air to recover or attack foes trying to flee into the air. Can pounce in any direction the player shifts towards as well
B ^ Alternative: Stormlift - A more unique one, mirroring Hero's Special ^, Thrall surrounds himself with the winds to shoot himself skyward to recover as the Whirlwind is what will cause damage to foes.
B v: Sunder - Taking the name from Heroes of the Storm, this move is basically Earthquake (Either as Metagross does it or how he does it in Warcraft 3) as he slams Doomhammer into the ground that trips and stuns any opponents around Thrall.
I cannot suggest anything special for references for his other attacks besides his lighter attacks probably being one handed use with his hammer with Smash attacks using both arms. But I can easily point to other references that can be done. First, his taunts can easily be cheers or warcries of 'Lok'tar Ogar" (Victory or Death in Orkish) and "Storm, Earth, and Fire; Heed my Call"; An Easter Egg for the Warcraft III for when a Shaman was built that is also refrenced at the start of the song 'Power of the Horde'.
As well, Thrall can easily get two different skins that can reference many things. His 'Warchief' skin references Doomhammer's armor which he wore from the tutorial of Warcraft 3 until Cataclysm. Alternate schemes can offer a more red armor and skin tone to reference the Horde and Garrosh Hellscream, Black skin to refrence Doomhammer and the Blackrock Orcs and even white along with the look of a Death Knight to represent the Scourge or his Hearthstone only appearance as such.
His other 4 outfits can use his 'Shaman' outfit from Cataclysm to Legion. For other options, You can give him Purple to reference his longtime friend (despite many issues): Jaina Proudmoore, black to reference Gul'dan who was the one to corrupt the orcs and lastly a Blue robe to represent the Alliance as well despite it being perhaps the most clashing idea for him.
Lastly, despite my build up of all this... This character is a longshot impossible dream due to the fact Warcraft has never had a game type that would work well on a Nintendo console. Blizzard has the option to many second-hand studios to make new titles for their franchises and yet the most seen is Diablo Immortal which is a phone game being developed by an outside Chinese developer that no one cares or talks about online despite it's release. If Thrall were to get in, he would completely need to smash the notion that you needed to have a series on a Nintendo console. I hope more people read this and support Thrall since this is a legit good character with lots avalable to make it happen that is squashed under a bunch of lesser characters who have to longshot what they have done to even get in.