Power of Creation

Castellan Casmus claimed that a Time Lord's ability to "manipulate" Time and the "substance of the universe" with "a thought" was the power of Creation. Upon sacrificing himself to destroy Tannis, the Seventh Doctor claimed that the Time Lords had "held this power for millennia" not so that they could use it, but so that they could prevent an "abomination like [Tannis]" from taking it for himself and using it to take over the universe. (WC: )