Seeing that both aren't too looked into a whole lot stat wise after late game as the basic shield is outclassed by every other shield and the Dashing Shield is commonly used at 0 star, at 10 stars they should have a new enchantment path to utilize new and same functions.
For the Basic Shield at 10 stars, a new enchantment path: Reflect.
Comes with two stats, Resistance and Reflected Damage, both having their value based on x%. Resistance dampens the damage taken while Reflected Damage copies the enemy's attack value at percentage. At +1, Resistance starts at 1% and Reflection Damage starts at 4%. At +21, Resistance is at 21% while Reflection Damage is at a full 100%, meaning it hits with the same amount of damage the enemy did. The reflected damage is instant, so when the enemy attack hits the shield, it immediately damages the enemy.
For the Dashing Shield, very short and simple addition for 10 stars, lowering cooldown. At +1, lowers the cooldown to 44 frames (1.47s), and at +21, lowers it to 15 frames (0.5s).