Immortal Blackbird

Immortal Blackbird sigil

Increasеs Mаx HP by 20%.
When thе Mod has а Shield active, increases Crit Rate by 5%. When the Mоd grants a Shield to a teammate or to themself, increases the ATK of the Mod granted with the Shield by 15%, as well as their Normal Attack DMG by 20%, for 10s. Effects from multiple Sigils do not stack.

Source: Limited Event Shop