His entire story evolves around The immortal Emperor , he served as a wrath for 300 years and learn whatever he could about the emperor only to betray him afterwards . He waited for that Jedi who he saw in his visions and in vanilla story he helped Jedi Knight . Though we all know Vitiate survived and his story continued , but Scourge was left out from all of it. That is why probably the biggest disappointment for me , story wise in KOTFE and KOTET was how Lord Scourge did not show up at all . Lord Dramath could have been easily replaced by Scourge as a supporting character who helps to destroy the Emperor at some point in a story , either sacrificing himself in a process or just fighting in some way to help the Outlander . Which would conclude his story , but it wasn't .

So we have one of the most interesting , conflicted (at least to me) character who's entire goal was to kill the emperor and yet after Vanilla story has ended he did not say a single thing . In SOR when emperor emerges , no comment from him either , KOTET or KOTFE nothing . At this point his return should not be just a returning character who you can talk and then get as a companion . Please do not make him a simpleton . Do not dumb him down . He has a rich history and immortality at his hand , passion to feel again , he was eager to learn and grow as a person and was not simple minded sith who only blindly followed the sith code . He was more .

There are few ways to address his absence without screwing everything up .

The first would be that let's say emperor's first original body is somewhere in the outer rim in a bacta tank , he discovered that and investigated it . And he knew that even if Valkorion died his spirit would survive , so he went to cut off the snakes head rather than the tail . Something like this . This is my random example , but all I'm implying is that Scourge never stopped for his quest to destroy his former emperor . His role in destroying Vitiate was major , not minor .

The second story that Scourge could follow up is to stop being immortal and to regain ability to feel again . For that he would need a sacred ancient sith ritual or make it a healing Jedi ritual , make a conflict that Jedi do not want to heal a Sith or even that Scourge is trying to find a jedi in thi galaxy who did survive and has the ability to heal him . This way you have an adventure(quest) to go on to find a ritual or an outcast Jedi healer who can help Scourge and you need to convince him to do so . This way it's a redemption story in a way . A "sith" who rather live a normal life but at least could feel again ( Similar to Barbossa from POTC 1)

These are two variations that his character arc could continue . Maybe not exactly like i described , but the themes i carries , one the story of emperor and the other is his quest to feel again .

Lord Scourge in swtor was never hungry for power or had an ambition of dominance and ruling an empire . Please do not make him a random boss fight of a big bad Sith who returned and now for some weird reason threatens the outlander .

and most of all , bring back Lord Scourge!

Actually ...

There have been unconfirmed reports that both Scourge and Kira were spotted in Monaco in May during the 2019 Grand Prix. Since then it's been anyone's guess. Kira may have been in seen somewhere in the French Riviera near Marseilles ... but again this is also unconfirmed.

This same principle goes for Kira too. Both of them should have been front and centre in KOTFE / KOTET. Scourge even mentions that Kira is special when he helps you break out of Vitiate's fortress over DK. At this point in the story (keep in mind this includes KOTOR too) Kira and HoT are the only people to ever manage to resist the Emperor's mind controlling influence. Then suddenly neither of them are around in KOTFE.

Now, I can forgive this if their return is meaningful and as you say turns out they did play some sort of significant role in Valkorion's demise. If this unfolds in the story and not as a two minute cut-scene, then they will have done justice to both characters.

At the moment, the hope of the return of these two characters in 6.0 is the only thing holding me in the game. If they return in a weak fashion or if its just another tenuous two minute cut-scene, then I can't imagine me staying around beyond playing the expansion on my mains.