The mc is transmigrated into the body of an cold-blodded alpha genral in military and I think the mc in real life was an actor and the alpha genral is very evil, then he goes into a shopping mall for some reason which then was attacked by outsiders but with the help of ml and mc they save everyone and later he turns into a Omega, and the ml is also an general in the military. And they go on a Mission together and for that join a jail undercover. And the terrorist i think are the aliens who can mind control or something That's all I remember.
Is it maybe 'The Virtuous Omega Disguised as the Vicious Colonel'? https://www.novelupdates.com/series/the-virtuous-omega-disguised-as-the-vicious-colonel/