The best replacement for callisto is xena.

The best alternatives to callisto are rated as following:
★★★★★  xena
★★★★★  storm
★★★★  deneb
★★★★  velasca
★★★  regor
★★  chronos
★★  laudis
★  propus
  miele leo
  calypso
  rana
  daphne
  alti

Your alternative for callisto is not listed? Suggest!
Speaking about callisto, one probably shouldn't forget about xena.

Other search terms related to callisto and their ratings are:
★★★★★ xena
You have in mind a companion for callisto and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of callisto in all years. Click on graph for more.
callisto
xena
storm