Giant Reach: When this character makes a close attack, instead of
choosing an adjacent character (or characters, if able) for target(s), you may use IT: Hindering and target character(s) within X squares and line of fire.

So as his effect reads to target others within LOS, does the Giant Reach ability to ignore hindering terrain take effect here to hit a stealth figure? Or is this effect its own independent effect which would would have nothing to do with giant reach due to no mention of adjacency? Hence no LOF could be drawn to the adjacent stealth figures.

The close attack made by the retaliation should also activate Giant Reach. Hindering terrain would be ignored.

For reference :
https://win.wizkids.com/bb/viewtopic...27628d2#p31994