If you are under the effects of Viscous' cube ability, the player will still take damage to their shields.
View attachment Viscous Shield Damage.mp4
Viscous's splatter and Vindicta's Crow familiar can also deal damage to cubed players (including allies, but Viscous only does shield damage).
View attachment Vindicta Team Damage.mp4
Viscous's splatter can even damage yourself.
View attachment Viscous Damage Self.mp4
View attachment Viscous Shield Damage.mp4
Viscous's splatter and Vindicta's Crow familiar can also deal damage to cubed players (including allies, but Viscous only does shield damage).
View attachment Vindicta Team Damage.mp4
Viscous's splatter can even damage yourself.
View attachment Viscous Damage Self.mp4