Warning: SPOILERS for Star Trek: Discovery’s Series Finale - “Life, Itself”
Summary
Elias Toufexis portrayed L’ak in 7 episodes ofStar Trek: Discoveryseason 5, but did he return to play the late Breen rebel inDiscovery’s series finale, “Life, Itself”? Written by Kyle Jarrow and Michelle Paradise, and directed by Olatunde Osunsanmi,Star Trek: Discoveryseason 5, episode 10was a super-sized episode that concluded Captain Michael Burnham’s (Sonequa Martin-Green) hunt for the Progenitors' treasure before flashing forward with an epilogue that gives Admiral Burnham and the USS Discovery an emotionally poignant ending. Meanwhile,Star Trek: Discovery’s finale’s ending is more open-ended for L’ak, his lover, Moll (Eve Harlow), and the Breen.
L’ak died inStar Trek: Discoveryseason 5, episode 7, “Erigah”, which revealed he was the Breen scion and direct blood descendant to the Breen emperor. L’ak was the key to the civil war between the Breen factions to succeed the late emperor, but L’ak turned his back on his people out of love for Moll. L’ak and Moll were on the run for years with an Erigah (blood bounty) on their heads. Finally captured and held aboard the USS Discovery, a mortally wounded L’ak miscalculated his dose of tricordrazine as he tried to enable Moll’s escape, and he gave himself a fatal dose. ButMoll took L’ak’s corpse with her when she allied with the Breen to find the Progenitors' technology.

L’ak’s corpse appeared in the final three episodes ofStar Trek: Discovery, both with and without his Breen helmet. L’ak was the first Breen ever to remove his helmet inStar Trek.
Star Trek: Discovery Season 5 Returning Cast & New Character Guide
As Burnham seeks the universe’s greatest treasure in Star Trek: Discovery season 5, she’ll need help from a host of new and returning characters.
Elias Toufexis Didn’t Play L’ak In Star Trek: Discovery’s Finale
L’ak’s corpse was played by an unknown actor
Although L’ak appeared in the final three episodes ofStar Trek: Discovery, “Labyrinths”, “Lagrange Point”, and “Life, Itself”,Elias Toufexis did not play his Breen characterafter he departed the seriesfollowingStar Trek: Discoveryseason 5, episode 7, “Erigah”.Screen Rantreached out to Toufexis about who played L’ak inStar Trek: Discovery’s series finale, and this is his response:
Elias Toufexis didn’t need to play L’ak anymore after “Erigah” since the Breen was just a corpse inStar Trek: Discovery’s final three episodes. Although,Toufexis regretted not returning for Jonathan Frakes' episode, “Lagrange Point”, which is the final episode ofStar Trek: Discoverydirected by theStar Trek: The Next Generationicon.An uncredited actor played L’ak at the end ofStar Trek: Discoveryand wore the costume and the mold of L’ak’s head.

Curiously, L’ak was wearing his helmet when Moll placed him in a portable pattern buffer inStar Trek: Discoveryseason 5, episode 9, “Lagrange Point”, but he emerged without his helmet in the Progentors' dimension inStar Trek: Discovery’s series finale.
What Happens To L’ak, Moll & The Breen After Star Trek: Discovery Ends?
The fate of the Breen civil war is an open question.
An open question left behind byStar Trek: Discovery’s finale that’s bigger than who played L’ak is what becomes of L’ak, Moll, and the Breen? Under the command of Captain Rayner (Callum Keith Rennie), with help from Ambassador Saru (Doug Jones), theUSS Discovery executed a saucer separationand spore jumped the Breen dreadnought and the ship controlled by Primarch Tahal (Patricia Summersett) to the Galactic Barrier. Without a spore drive of their own, Rayner estimates it will take them 20 years to return. But that only eliminates two Breen factions,leaving the result of the Breen civil war and the next emperor’s identity dangling.
What becomes of L’ak’s corpse?
Meanwhile, Moll could not use the Progenitors' technology to resurrect L’ak as he would only come back physically, not as the man she loved. But what becomes of L’ak’s corpse, which Moll returned to herportable pattern buffer?Is L’ak ever laid to rest?After all, Moll’s next stop is a Federation prison, after which Doctor Kovich (David Cronenberg) has plans for the former courier. PerhapsStar Trek: Starfleet Academy, the nextStar Trekseries, will address what ultimately becomes of L’ak’s corpse, Moll, and the Breen afterStar Trek: Discoveryends.