The sunlight dispelled the darkness and drove away the pigmen who were familiar with the darkness of the underground Beast Lair and hated the light.
Light represents hope, suppressing the beasts, just as humans drove away beasts with firelight countless millennia ago.
In the battle just now, many people were injured, or rather, accumulated injuries that hadn't received proper treatment.
They had all learned battlefield first aid, but were powerless, as the bandages and herbs had long been used up in the battle.
And Alhazred encountered problems; the continuous spellcasting had weakened the distance between him and the Void, making it difficult for him to display true prowess, even controlling his own body was challenging, let alone saving others.
Thus, Junia basically took on the heavy burden of healing, leveraging the holy relic, the Iron Torch, to achieve initially effective results, but soon her strength was drained.
