The goading is a supernatural event (without saying so which is the problem), because what it demands is not realisticly possible in all the situations the power is i allowed to be used for. Now, that may not be an interpretation you care for, but its not a fiction about mundane events.
There are two things I don't get about this.
(1) The ability only creates fiction when it is used. The notion of "allowed to be used" only applies in the real world, as a fact about the relationships between the participants in the game and their collective creation of a shared fiction. It's not a notion that has any meanning within the fiction.
(2) The ability clearly intends - by its reference to
insult - that the event that occurs, in the fiction, is one that occurs via ordinary psychological processes (namely, the enemy, being insulted, is goaded into attacking). You may think that's a terrible fiction, but that doesn't mean the fiction is about
something other than what it is about.
I'll give some concrete examples from a RPG I play that is not D&D. In the Prince Valiant RPG, a player can sometimes gain the ability to use a "Special Effect". One of those effects is Kill a Foe in Combat:
Any enemy, whether newly made or long known, can be destroyed with this Special Effect, guaranteed, as long as the selected character is armed and capable of serious offensive action. The character must be in combat with the chosen foe at the moment, and not in a disadvantageous situation (surrounded by enemies, injured, his back turned to the enemy). The selected character makes an attack, and the attack is miraculously successful, killing the foe instantly.
By your measure, this ability must be supernatural because it is "unrealistic" that the knight in question can kill anyone or anything. But it is not. I can tell you that this ability has been used twice in my campaign. The first time, the character whose player used it was jousting with a much more puissant knight. The PC's lance splintered, and a sliver of wood flew through the visor of the NPC knight and killed him. The second time, the character whose player used it (the same character and the same player) was in the water fighting a giant crocodile. He was able to swim beneath it (a successful Brawn + Agility check was made, which ensured that the character was not "in a disadvantageous situation") and stab it in its soft underbelly.
Both those events, although improbable and perhaps even miraculous, occurred through ordinary physical causation. Neither was supernatural.
Another Special Effect is Incite Lust:
This Special Effect makes one character’s primary thoughts turn to lust for another character of the opposite sex. The user of the Special Effect may select any two characters, even Adventurers, as the lustful party and as the object of desire. The emotion is permanent.
The current Storyteller will have to make a ruling as to how the lustful character behaves. If the lustful character is an Adventurer, the controlling player decides how lust affects his character. A Storyteller may veto the controlling player’s wishes only if the intended behavior is unrealistic.
If this Special Effect is used to permit one character to dominate another, common sense and logic should be used. The character will not jump off a cliff for the object of his lust, nor will he necessarily wish to marry her. This can be a cruel Special Effect to use, especially if the object of lust is unattainable.
In our game, a NPC had this Special Effect (with herself as the object of longing) and I as GM declared its use on the same PC as killed the NPC knight and the crocodile. It occurred when the PC rescued the NPC from attacking knights, swinging down on a rope from the castle wall and taking her in his arms. Naturally, hilarity ensued - but the point of the example is that nothing supernatural happened in the fiction. The PC becoming infatuated and obsessed with this NPC (to an extent that seriously threatened his marriage) was a result of purely ordinary human interaction and the attendant psychology.
The ability that
@MuhVerisimilitude has suggested is just like these ones: it is a "special effect" that the player can use, which establishes that a certain thing happens in the fiction (ie the goaded enemies attack the character). That event is not a supernatural one.
