This may be a confusing question. The middle initial will with be L or R (family names) I like nicknames such as CJ, JT, DJ, ect. But I can’t think of a first letter/name that would form a good nickname with L or R as the middle name.
I kinda like CR? So maybe [name_m]Christopher[/name_m], [name_m]Christian[/name_m] or any other name really that starts with C. I also think TR works
It might be too [name_u]Dallas[/name_u] for you, but [name_m]JR[/name_m] comes to mind. Any J name would work — [name_m]Jonathan[/name_m], [name_u]James[/name_u], [name_m]Jasper[/name_m], [name_m]Jonah[/name_m], [name_u]Jordan[/name_u], [name_m]Julian[/name_m]…
You could also arrive at a two-letter nickname through the first and last initials, or through the first name alone:
[name_m]Alaric[/name_m] nn. AC
[name_m]Elijah[/name_m] nn. EJ
[name_m]Jacen[/name_m] or [name_m]Jayceon[/name_m] nn. JC
[name_m]Jonathan[/name_m] nn. JT
[name_m]Thackeray[/name_m] or [name_m]Tucker[/name_m] nn. TK
Etc.