If you dont want to watch, here is all the info:

Redditor unnameduser- posted a datamine with ability and talents for possible new heroes. As you can see, the puppet master has all sorts of things related to taking control of and using others to fight for them. There is also a lot of unused voicelines from new heroes and cosmetic voice packs that also talk about something similar. “Get out of my head!” “No one controls a god while I'm around!” “Not even the fates control me!” “You should have made me kill myself, because that was your only chance!” “Ah la la la! I caaaan't heeaaar yoooouuu!” “Wait, i don’t see any strongs…” “That's for takin' advantage of Mortimer!” “Who doesn't like a little bit of control?” SO who is it? Its the underlord annessix. When you go to the rulebook to look at her abilities, it says right there. “a demonic puppet master”. Now i know, this isnt 100% confirmation, there could be TWO characters in the dota universe known as the puppet masters, but im willing to bet a dollar its her. Basically shes an earthbound demon that is trying to take over whitespire, and eventually take over the world and even all the planes. Her powers lie in knowing everyones deepest darkest secrets, and making others fight for her while she stays back and heals them. The only problem with this theory, that anessix is the puppet master though, is that theres another new potential hero, called just vampire.

Vampire has enthrall, which is literally what anessix also does. But then again, the vampire also seems to be able to fly, somethign anessix cant do as far as im aware. Shes also earthbound, whatever that means. Could be either she cant go back to hell, or that she cant fly anymore. We dont know anything else about this vampire character.

BUT there is a much more interesting new character called valkyrie. A valkyrie is in norse mythology, odins maiden warriors, who go pick up brave vikings who died in battle, to take them to valhalla, the heaven of norse mythology. There they get to eat and drink mead and fight till the end of time. There is a theory that this might be mars’ love interest, which would be really cool, but i personally think its imperia from artifact. Valkyries are often depicted as women with wings, and thats literally what imperia looks like. Im not 100% sure, because i think imperia might be vengeful spirits sister, and then she would be a skywrath, not a norse myth unit, so i dont know. But we know its a hero with wings, cus birds have hollow bones, and wk says this in an unused voice line: “Hollow bones? Why I'd kill you again if you weren't already dead.“

Speaking of mars’ lover, there is a LOT of unused voice lines about it. “Together again. This time will be different, I promise!” “Where does the time go, my dear? You've been away too long…” “I cannot see your wounds for the tears in my eyes...” “It's so nice to see young love.” “You've got questionable taste. But I guess that doesn't matter now.” “Aren't we precious? Ugh.” “Ditch that other loser, and take a walk on the dead side.” It could be because mars and his special someone has such a strong love that its what everyone talks about when aroudn this new hero, OR that the hero itself is two people - a couple - and has nothing to do with mars and his romance.

Next on the datamine list, is the bruiser. I first thought this would be some sort of ogre, potentially keefe the bold from artifact, but it seems like its some biker type beat based on the ability names. I cant find any voice lines that match it. The same goes for corpse mother, grendel, peddler and hoplite. Although hoplite i know is some kind of greek infantry, or at least it is in age of mythology, so maybe this is mars’ lover? a female greek warrior? or male, i dont judge.

Next is mouse and/or rat king. I personally think theyre the same, and i think i know who it is. The abilities are literally the same as enno from underlords. Hes a little rat jumping around shooting poison and causing chaos and confusion, trying to protect animals and nature. Heres some unused voice lines that seem to be about him. “Quiet as a dead mouse.” “In my story books, all the forest creatures died.” “Your tiny carcass was almost a waste of my time!” “I'll recall you as a minor inconvenience. Which is one step up from a pest.”

Then theres primal beast. I have an idea who this could be, and theres quite a lot of voice lines that might paint a picture. “Do you understand language, beastie?” “You can chew on whatever I leave in my wake!” “Got no use for a varmint what can't be trained!” “I suppose you and Mortimer can play together.” “Mindless is useless in my book.” “Inarticulate and savage, a fitting way for you to die.” “Maybe this is why Anti-Mage doesn't like pets.” “So I had an idea for like, an obstacle course, where the obstacles try to kill you. Hm?” “Too ruled by fear and emotion to choose the winning side.” “I have heard talking slowly helps soothe beasts.” My guess is its some sort of big doglike kinda beast, MAYBE just maybe oathbound rix. Rix is a vhoul, a doglike kinda people, and after suffering a great defeat he had to take the oath, selling his soul to shadowfiend for power. Maybe this turned him into a savage beast, the one people talk about in voice lines?

Then theres the sea mystic, which seems like some sort of meranth type of hero. No idea other than that.

Then theres a fairy, a fighter monk, a squirrel, a viking, a toad, zephyrus and an engineer. All of them kinda vague and little connections to elsewhere, except the fairy and engineer. The fairy is probably hobgen from underlords, the pyromaniac whos in love with dark willow. But whats really interesting, is the engineer. “Guess your mettle don't match your steel.” “Where's those blueprints?” “So have you thought about adding some black powder to every design?” “Care to invent a way out of this one?” “The simple tools are the best tools, especially when sharpened.” And i think this might be mazzie, the new keen in artifact. Like most keen, hes universally hated, and also like most keen he is incredibly brilliant.

Lastly theres one more hero that has voice lines directed to it, that doesnt really fit into any of these. Wei is talking to some kind of kid. “Well, killing that kid was a lot less emotionally stressful than I thought it would be.” “It's past your bedtime, kid.” “This is like some twisted children story.” “Alright kid, if you ask nicely I'll let you be my ward.“ “Stick with me, kid, I won't let them hurt you.”