Steps of reproduction: 

-Have at least 1 in purple or blue magic (as no other magic currently has anchor spells I believe)

-Make sure no blue or purple crystals are in your paws/equiped

-Use wind whisper, teleport or summon on a character that's offline

-Spell fizzles automatically if the critter is offline

EDIT: This doesn't seem to be able to crit fail and also costs mana

I haven't checked if you can crit fail this yet or anything yet, and won't be able to for a day or so.

Additional feedback:

Also, you can "reset" a spell to check who's online. All you have to do is check your spell anchors a couple times and if anyone is above a spell anchor you're carrying, it stays the same. If you check a couple times and someone doesn't move, they're likely online.

If possible a way to easily check if someone's online using magic would be appreciated