Hyra moves to the side, firing a Sunbeam, but stumbles as she lands and falls with a clatter. Both enemies resist the worst of her sunbeam.

As Lanius fires his arrows at the priest, Gothmog's fiery whip snakes out to attack him.
Spoiler
Show

Disadvantage - can't see his target.
Attack (1d20+14)[26] or (1d20+14)[20] for (2d6+8)[15] slashing and (3d8)[13] fire, plus DC 20 Str save or pull closer
(1d20)[3]
It doesn't keep Lanius from moving, so he still ends up where he is going I think.