Lucas's personality and appearance stays the exact same, but here are the important history points:
1. Born into Cranford and Morgenstern.
2. Moves to Seattle (Age 4.5)
3. Abuse begins, slowly (Age 5). Isaac's parents die, leaving him to go to Germany more often.
4. Meets Collin Hannula.
5. Dec 4, age 9 - Intentional Chest Stab. Dec 16 - Accidental Side Stab, requires staples.
6. Dec 18 - Isaac dies by the hands of his wife.
7. Sep 13, age 10 - Adopted by Moncriefs, changes name.
8. Sep 20, age 10 - Nightmares begin
9. Oct 11, age 10 - Diagnosed with PTSD
10. Age 14, Lucas loses his virginity, it goes downhill from there.
11. Age 15, Derek Armstrong happens, he is raped. There's that trauma to deal with, and he can't drink alcohol without experiencing flashbacks about it.
12. Age 15, diagnosed BPD.
13. Age 15, Russian Roulette is formed.
14. Age 16, tried ketamine, messed with the nightmare medication, so drugs are out.
15. Age 17, Bathtub Incident (tries to kill himself the first time --> leads to self-harm problem)
16. Age 17, Collin (Best Friend) talks to Lucas about Fears and Worries about his recklessness. (This and the above incident is what motivated Lucas to stop being so reckless sexually.)
Those are The Important Plot points, the most important are italicized. I tweak those with every AU, so say for the Titans AU, you add in there the plot points of learning about his powers and how to use them, and moving to Chromium City at 19. As for Culture Shock, Lucas moves to Provo at age 16 -- because of this, he never attempts suicide and loses most of his contact with Collin, so he never really stopped being reckless when it comes to sex. (But in that AU, Lucas is 16, so who knows.) 20s AU? A lot of that is changed. Collin and friends don't exist, both Luana and Isaac were killed in a shooting, Derek also doesn't exist... in that AU, lots have been changed.