Hunt your friend for content with the /track command and a compass
works in the nether! (I think)
"I am large." - Cahd
/track <player>
to track someone with a compass/trackCoolDown <seconds>
to change how fast the compass updates
Simply Download the latest Translucency.jar and place it in .minecraft\mods
or drag and drop via multimc/prism Edit instance > loader mods