Stalwart Shell is a Charm in Hollow Knight. It increases invincibility frames and reduces hit recoil.
Usefulness
This item primarily shines in some boss battles, especially ones where it is difficult to avoid getting hit. The longer invulnerability time can provide a window to attack a boss with impunity, potentially overwhelming them with sheer damage.
It is also useful in the Trial of the Fool, which features many encounters with enemies whose attacks are hard to dodge.
How to Acquire
Bought from Sly in Dirtmouth for 
200.
Charm Interactions
 | Baldur Shell Applies Stalwart Shell's effect when Baldur Shell is triggered. |
 | Thorns of Agony Decreases the time taken for thorns to activate after being hit. Increases the animation speed and leaves extra invincibility frames after the ones consumed by the animation. |
 | Quick Slash Especially efficient in combination with Quick Slash, allowing the Knight to quickly deal a large amount of damage. |
 | Fragile Strength Especially efficient in combination with Fragile Strength, allowing the Knight to quickly deal a large amount of damage. The same is true with |
 | Quick Focus Useful to provide a window to focus soul and heal when used with Quick Focus. |
 | Carefree Melody Applies Stalwart Shell's effect even when the damage is negated by Carefree Melody. |
