I like [name_u]Emory[/name_u], but the only person I know with the name is female, so I may be a bit biased as to its female usage. Because of this, I would try to pair it with a more traditionally masculine name.
In the spirit of being honest, [name_f]Shadow[/name_f] and Wintergreen don’t really work as names for me, and would provide ample opportunities for teasing as he grows up. Perhaps substituting something like Shadrach, [name_m]Chad[/name_m] or [name_m]Charles[/name_m], [name_m]William[/name_m] or [name_m]Wilder[/name_m], that have similar sounds, would be a better choice.
[name_u]Emory[/name_u] Shadrach, [name_u]Emory[/name_u] [name_m]Charles[/name_m], [name_u]Emory[/name_u] [name_m]William[/name_m], [name_u]Emory[/name_u] [name_m]Wilder[/name_m] (as suggested) are all nice
[name_u]Emory[/name_u] [name_m]Slater[/name_m] and [name_u]Emory[/name_u] [name_u]Justice[/name_u] are definitely cool
[name_u]Emory[/name_u] [name_m]Ronan[/name_m] and [name_u]Emory[/name_u] [name_m]Ryder[/name_m] are kind of tongue-twisters. Maybe consider flipping them? [name_m]Ryder[/name_m] [name_u]Emory[/name_u] or [name_m]Ronan[/name_m] [name_u]Emory[/name_u] have nice rings to them.
For [name_u]Emory[/name_u] you could use nn [name_m]Morry[/name_m]/[name_m]Morrie[/name_m], [name_u]Mo[/name_u], or [name_m]Ry[/name_m]
[name_u]Emory[/name_u] is okay, but it feels all-girl to me personally.
nn: [name_f]Em[/name_f], [name_f]Ree[/name_f], [name_u]Reese[/name_u], Emor
[name_f]Shadow[/name_f] - too funky for me, best as a mn
nn [name_u]Shade[/name_u] ?? i dont know lol
[name_m]Slater[/name_m] - okay, but comes with a very specific image with me - tough guy, jock I think it’d be hard if he wasn’t that way; mn
nn [name_u]Slate[/name_u], [name_m]Slade[/name_m], [name_u]Tay[/name_u]
[name_m]Ronan[/name_m] - love!
I don’t think this needs a nickname!
Wintergreen - doesn’t feel like a name to me, a little too whimsical, if anything would be best as a mn
nn [name_u]Winter[/name_u], [name_u]Green[/name_u], Greens, [name_u]Winn[/name_u] (I like this!), [name_f]Greer[/name_f], [name_m]Will[/name_m] (a stretch), [name_m]Ian[/name_m] (also a stretch)
[name_m]Ryder[/name_m] - my fav from your list
this doesn’t need a nickname either!
[name_u]Justice[/name_u] - I’m on the fence with this one but I think I’d warm up to it, would like it best as a mn