Tummbutt has unique power that can be useful for many different situations. First off, Tummbutt can use his power at any time, which is very useful. He can be sent to Limbo to reorganize all the attachments legally in any pool (an opponent's or that of his player). Most often this will be used on an opponent's pool to either spread all the magic items from one powerhouse around to several weaker champions, to take them off a champion with an undersirable power (like immunity or the power of Chernevik (347/4th), or as a preperation for another card (for instance, putting all the magic items on one champion, then casting Wish (46/FR) on that champion).

All of these uses, especially the later two, make him a decent choice for a tournament deck. However, this won't happen all the time, since he can cast no spells or use other support cards.

Another good use of Tummbutt is to put him into combat defensively, then use his power, saving him and forcing another champion to attack. This should not be done while attacking however, since the opponent would be able to draw spoils with Tummbutt leaving play.

Overall, Tummbutt is not a bad card that will find a niche in the tournament setting, but generally not so much if general fun games.