Don't make Luthen a non-combatant like MM. He's very much a combatant.
He would have to operate differently, though. The best thing for Luthen is to make him a VERY powerful toon with an Omicron that prevents anyone (ally or enemy) from targeting an ally with any ability and from sharing stats passively with any toon. If that isn't powerful enough, add on that it prevents all AoE damage (you can only damage the toon you're targeting). And, of course, Luthen and all Luthen allies ignore taunt.
In Luthen's world, everyone is on their own and sneak attacks can come from any direction. Characters can affect allies with things that grant buffs or passive benefits (like Barriss' zeta allowing each toon to heal when critically hit) only so long as the it doesn't require targeting a specific ally with an ability on your turn.
It could (would?) make him a hard counter to JML and if you shut down AoE damage you severely limit Lord Vader squads. Jabba, on the other hand, would make short work of him by piling thermals on Luthen and his allies one at a time.
It's also just super moody. That's an ability that really brings out the character of Luthen and translates it into game mechanics. Frankly, I know that they try to do that sometimes, but I wish that they could and would do it more. Like Barriss. She's a Jedi who turned to the dark side. But not only that, she's a Jedi who conspired to blame Ahsoka for her own crimes. What if at the beginning of her turn she dispelled all debuffs on herself and granted a random debuff of the same type to any other LS UFU or Jedi, one copy for each distinct type of debuff? (She cannot dispel her own debuffs if there are no active LS UFU or Jedi allies.)
It can still be an advantage, by reducing the duration of the debuff to 1 turn regardless of the original duration and by reducing multiple copies of a debuff (like DoTs) down to 1 copy. But it's similar to the Sith ability to self-cleanse at the cost of health (see Traya) which characterizes Barriss as Sith-adjacent, and it simulates blaming someone else for her own sins.
There's just much more that could be done with translating the feel of a character into the mechanics of SWGOH. I will give them that it's better than it used to be (the first 30-40 toons released right at the beginning of the game seemed to have little to no attempt to consider characterization at all), but I'd like to see them do more. Those are the touches that make a game great.