My scouts and seaponies have reported to me tales of a very powerful surface worlder magician. He has helped stop Tirek the centaur, fought windigoes, and invented a thousand different spells. Some rather useless, but others incredibly complicated, that can mess with time itself.
This pony bodes watching, or as much watching as can be done. He probably isn’t a threat to Aquestria proper, but our outlying communities may be affected by whatever magical fallout he may leave.
And if you think I’m wrong for assuming he will leave a magical fallout, diary, he’s a super-powerful magician. He’s going to leave some kind of fallout in his wake.