Timestream isn't in Set 18. Last seen in Set 17 (Patch 17.8).
Appears in:
Set 17 (Patch 17.8)
What it does
Your team gains 100 Health. Timebreakers gain 7 Health and 0.3% Attack Speed every time you reroll (including free rerolls). Gain an Ezreal and a Pantheon.
(Health: X, Attack Speed: X%)
Some values aren't in Riot's published Set 17 data (shown as X).
