Snowballs that go in a straight line towards the spawn point in 3d, at a speed that indicates how close you are (they slow down). At 10,000 blocks they're arrow speed or more. You can sprint to keep up with them around 1000 blocks out. By 10 blocks they're just poking around. Thus you get direction and distance estimate.
Oh, and they're on fire. Did I mention they were on fire?
Tried but failed to spawn a firework burst (or just a firework would be OK) when they get below a distance of 8 from target (i.e. when we give up on 'em). I'd like to have the take-over also trigger bursts. Green if it's your own leading you home, red if it's a take-over.
With the journey process being this nifty, definitely don't want 'reroll, then /kill' to be the norm. It should be pretty exciting chasing these things to the goal. We should force in a big stack just so that players can load a bunch into their inv. The spectacle of a big line of these is glorious as they converge on the location.