Aliasing kha'zix → kha'zix_(lol)
Link to alias

Aliasing tristana → tristana_(lol)
Link to alias

Aliasing master_yi → master_yi_(lol)
Link to alias

Aliasing blitzcrank → blitzcrank_(lol)
Link to alias

Aliasing galio → galio_(lol)
Link to alias

Aliasing zac → zac_(lol)
Link to alias

Aliasing anivia → anivia_(lol)
Link to alias

Aliasing fiddlesticks → fiddlesticks_(lol)
Link to alias

Aliasing braum → braum_(lol)
Link to alias

Aliasing cho'gath → cho'gath_(lol)
Link to alias

Reason:

Anything that's a common name (Zac) should be disambiguated just in case, while anything unique (Kha'zix) won't need the suffix.

Furrin_Gok said:
...anything unique (Kha'zix) won't need the suffix.

Suffix couldn't hurt, if for nothing else than consistency with other characters, and in a lot of these cases the one with the suffix has more posts.

+1 to Zac disambiguation, though