can kemper sound like a 12 string?

An electric 12 string has two sets of unison strings. You can program a similar sound - all six strings will be in octave pairs. This is a very musically useful sound

If you use the Pitch effect, set at +12, and set the mix to be a little bit quieter than the normal pitch strings, you can get a similar sound to an electric 12 string. Adding a bit of Detune, or a separate chorus effect can add to the effect.

Vox, Matchless, and vintage Fender are a sparkly compliment to classic 12 string sounds. If you are thinking Led Zep, Supro and vintage Marshall sounds may be what you want.