Take the light elevator down to the bottom of Weavenest Alta, then climb up the shaft until you can go right. Keep right until you reach a lava chamber. You'll need to complete the platforming ...

Those are all the Relics you can find in Hollow Knight Silksong. It's easier to find them if you know where to get all the maps from Shakra, plus how to navigate The Mist so you can reach the Citadel ...

You'll start Hollow Knight: Silksong with five masks, which means Hornet can take five points of damage before she folds. By the end of the game, you can double that HP by collecting Mask Shards.