The best replacement for shadow is sonic.

The best alternatives to shadow are rated as following:
★★★★★  sonic
★★★  silver
★★★  knuckles
★★  vegeta
★★  mephiles
★★  tails
★★  sonic games
★  mario
★  luigi
★  holy priest
★  disc for pvp
★  sage
★  sonic who would win
★  amy
★  snake eyes
★  no shadow
★  metal sonic
★  super sonic
★  assassin
★  shadow
★  blaze
★  sage swtor
★  shade
  keane
  sonic exe
  harley
  disc priest
  nazo
  disc
  v star
  duelist path of exile
  dark sonic
  solitude
  holy
  mewtwo
  assassin swtor
  discipline priest
  duelist
  kawasaki vulcan
  suzuki boulevard
  sportster
  v-star
  yamaha v-star
  yamaha vstar
  discipline
  sonic video
  vulcan
  honda spirit
  virago
  vending machine
  drag star
  magna
  rebel
  dyablo

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

Other search terms related to shadow and their ratings are:
★★★★★ light
★★★★ hands
★ sonic
rouge
You have in mind a companion for shadow and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of shadow in all years. Click on graph for more.
shadow
sonic
silver