Titanic Ultimatum

• WWizards of the Coast2008-10-01
  Official Ruling
  The set of creatures affected is fixed as Titanic Ultimatum resolves.
• WWizards of the Coast2008-10-01
  Official Ruling
  Multiple instances of first strike and trample are redundant.
• WWizards of the Coast2009-10-01
  Official Ruling
  If a creature you control already has lifelink, Titanic Ultimatum will give it a second instance of lifelink; however, multiple instances of lifelink on the same creature are redundant. You still only gain life equal to the amount of damage dealt, regardless of how many instances of lifelink the creature has.

Rulings via Scryfall