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: Death Comes to Time [+]Colin Meek, BBCi animations (BBCi, 2001-2002).)
This power was rooted in the ability to command and manipulate "data sets", the "root code" of reality, which told subatomic particles how to behave. (PROSE: The Minister of Chance [+]Dan Freeman, adapted from The Minister of Chance, The Minister of Chance (Arcbeatle Press, 2022).) After the Doctor punished the Minister of Chance for misusing his power and destroyed himself on Salisbury Plain, (WC: Death Comes to Time [+]Colin Meek, BBCi animations (BBCi, 2001-2002).) survivor members of his people, including the Minister, the Horseman, the Sage of the Waves, the Pilot and the Summer King, agreed to a "dissipation pact", lessening their innate powers by transferring them into talismans so as to make it less easy for them to slip into misusing them. Rathen, the half-human hybrid child of another survivor, also began to exhibit these powers, and, not being party to the pact, started misusing them again, creating major distortions. (PROSE: The Minister of Chance [+]Dan Freeman, adapted from The Minister of Chance, The Minister of Chance (Arcbeatle Press, 2022).)