As that long title said what do you want him to say in some random voice. You can request which voice says what. Heck you can even make him sing parts of songs if he knows them. Here is the list of voices I've heard him do.
Mickey Mouse (Disney)
Donald Duck (Disney)
Bugs Bunny (Loony Toons)
Edd (Ed, Edd, and Eddy)
Eddy (Ed, Edd, and Eddy)
Sans (Undertale)
Papyrus (Undertale) or Skeletor (Heman)
Stitch (Lilo and Stitch)
Edgy
High Pitched
Racist Japanese
Flowey (Undertale)
Himself
Mario (Mario) and Cartoon Mario (Super Mario Brothers Super Show)
Luigi (Mario) and Cartoon Luigi (Super Mario Brothers Super Show)
Toad (Mario)
Sonic (Sonic)
Kermit the Frog (Muppets)
Inkling (Splatoon)
FilthyFrank (FilthyFrank)
Once we have like something for each voice we'll begin recording him. This is going to end horribly...