After using Unown VSTAR's "Star Cipher" attack while Path to the Peak is in play, I then use Spiritomb's "Ticking Terror" attack to change the Defending Pokemon's Weakness to {D}. If my opponent removes Path to the Peak from play, what will that Pokemon's Weakness be?
The Weakness will be {P}. Once Path to the Peak is removed from play Star Cipher's effect will reapply, and the most recent Weakness-changing effect takes precedent.
Source: TPCi Rules Team (2022-11-10)
My Arceus V is active and I have Dunsparce with "Mysterious Nest" Ability on my bench. If my opponent uses Spritomb's "Ticking Terror" attack does Arceus V now have {D} weakness, or does "Mysterious Nest" keep it with no weakness?
The Ticking Terror attack would switch Arceus V's weakness to {D}, but then Dunsparce's Mysterious Nest would change Arceus V back to no weakness. However, since Ticking Terror says "Until the end of your next turn..." Arceus V would become weak to {D} if Dunsparce were to leave play or have its Mysterious Nest ability shut off.
Source: TPCi Rules Team (2022-03-31)
If I use Spiritomb's "Ticking Terror" attack against the Defending Pokemon and their owner moves it to the Bench during their next turn, does its Weakness return to normal?
Yes, since it is an attack effect, moving that Pokemon to the Bench removes it.
Source: Brilliant Stars FAQ; TPCi Rules Team (2022-02-24)
If my opponent has no Weakness and I use Spiritomb's "Ticking Terror" attack, will I do extra damage on my next turn due to Weakness?
If a Pokemon has no Weakness printed on the card, Ticking Terror will give that Pokemon a x2 Weakness to Darkness.
Source: Brilliant Stars FAQ; TPCi Rules Team (2022-02-24)