Partially correct. He had two lore, you threw two blue shields. So you remove both Lore.
According to the card, once he is at zero life points, it take a final blue shield to kill him.
So you needed one more hit.
None, and Troll is immune to [ SoS ]. Instead, the Troll uses Lore token “Life points”. Starting with 2 Lore tokens at his side, the Troll loses 1 each time a [ Blue Shield ] is rolled against him. Once he has no tokens left, another [ Blue Shield ] kills him.