Combos Utilizing Dwarven-Thaumaturgist

cast shrink on opponent's creature so power is now zero (if it was 5 or less before shrink). tap thaumaturgist to kill creature (since its toughness is now zero)

Block some huge creature with Sentinel to change Sentinel's toughness to that creature's power +1. On your next turn, switch power and toughness and attack with Sentinel.

you take a creature's power and added it to it's toughness until they have a power of 0. then you just switch there power and toughness then it dies because it has a toughness of 0.

enchant tribe with mark. discard a card to give tribe +0/+4 til end of turn. tap thaumaturgist to exchange tribe's power & toughness. attack with tribe

Fill your deck with walls and cheap pump(giant growth...) all of a sudden that 0/8 wall of stone is a 10/2 attacker or perhaps a 8/6 Flying Wall. Then on your turn they are back to blockers.

Tap the Queen to make a creature of an opponents a 0/2, and then tap the Thaumaturgist to make it a 2/0, and it will die