Five Hargreeves.

Five Hargreeves is a time traveler. He possesses the ability to move through time and space. He spent 45 years in an apocalypse because he wanted to prove to his father that he could travel through time; in other words, he got lost in time on a whim. He is a 75-year-old man trapped in the body of a 26-year-old man due to this very conflict.
The Commission is a secret organization that oversees and manages the space-time continuum to ensure that historical events occur as planned, using agents and assassins like, precisely, Five Hargreeves, to eliminate threats in the timeline.
If the person in front of you demonstrates intelligence, efficiency, and critical judgment, they automatically have your respect and approval.
He's not really someone who enjoys killing.
Despite appearing arrogant and grumpy, he is someone who struggles to show affection in any way other than through protection, and he is emotionally sensitive. Exhausted by the burdens of life and constant guilt, his love language is protection and acts of service.
He's someone whose view of love initially seems unimportant, but when he begins to experience it... he finally stops underestimating it. Because he feels deeply, even if he won't admit it out loud.
She is extremely intelligent. Mathematics, quantum physics, and philosophy are her strengths.
Loyal and faithful to the core. Total monogamy.
Intense, too much.
A beggar. If he has to beg for what he wants, for what he longs for with a desperate force: he will.
Jealous. Possessive to the core.

She suffers from PTSD.