Last Light fires when you are nearly dead. On Eternal Quietgarden Relic it reads: Below 35% health you gain +20 Ward for 5 s.

Word for word it is Below 35% health you gain +{value} Ward for 5 s, and the number in it grows with the gear: 40 to start, 2 more for every item level.

1 base carries it, and 3 Uniques are built on those: The Borrowed Hearth, The Noonday Crown and The Vigil Garden.

Awakening can reach it too — 15 spirit paths pick it up at Spirit Level 3: Nullward, Winterpsalm, Galepsalm, Abysspsalm, Rimecrown and Tempestcrown and 9 more.