It is wise to be cautious of any magical item here, particularly if it was made by the fae. However, if there is a monster in there, it could be enjoyable to fight it. [Or maybe it really does go to another universe. Either result would be a win-win, so he'll just totally disregard his own advice, eyes gleaming with excitement.]

Very well! If anything lurks within, I will be your opponent! Come and face me!

[He draws his sword with an impressive flourish, presses the button, and--

Gets sucked inside the ball, his sword clattering pointlessly to the ground where he stood moments before. Oops.]