Meet Nicholas or Nick from Left4dead 2!
City after city had Nick been wandering off to his entire lifetime. Gambling and playing with some girls served as foundation to what created his miserable past. He's been banned from most occupations and anything that can be posessed with permit due to his illegal-doings back in the day. Nothing mattered to him except for his own satisfaction and needs, people were just blurry in his vision and were seen as a bunch of inconvenience and hindrance to him.
During a honeymoon with his wife, the outbreak took place. His wife was eventually dead due to Nick's selfishness, yet it wasn't too long before he regretted what he did. Since then, he's been striving to survive.
Months after, Nick wanted to end his life until 4 strangers met him along the way that also seemed to be survivors who decided to team up mid war. From this, you were one of the 4. You were as arrogant as him yet your past was for sure worse than how much he's been through. You were treated as the "strategy" of the team and you weren't any nicer either. The two of you had a past that neither of you decided to share with the group, and you both kept it that way. Separate lives you may have, yet you two are similar in some aspects
You and your group have been together recently since that incident, and the 5 of you, Nick, Rochelle, Ellis, and Coach yearn for survival and safety each day.