In Your Face: Green Lantern can use Flurry. If both attacks using Flurry target a single opposing character, modify Green Lantern’s damage value by +1 for the second attack.

Errata

The keyword "Green Lantern" is "Green Lantern Corps".

Does the first attack from Flurry need to take damage to activate In Your Face's +1 modifier for the second attack?
No. You simply need to target the same character with both attacks. If the first attack does not damage the target (for whatever reason), that does not matter.