Instead of the default "Stamina" consumption that occurs upon the usage of a shield, shields should deplete Feather's stamina meter.

This could integrate especially well considering that it'll provide a more combat-oriented experience rather than the monotone 'more shields - more armor!' types of mods.

With integration in mind, shields should then support enchantments regrading the stamina system, such as the 'lightweight' enchantment. Possibly, more enchantments related to stamina consumption could be added to fit the theme. One example off the top of my head is the Energising Parry enchantment, which replenishes stamina upon successfully parrying a strike.

Overall, this is merely an idea that otherwise would've been stuck on my mind. Whether this becomes full integration, optional, or perhaps even not, this could easily make the mod stand out from other combat mods; not to mention the users' feelings of bliss when realising they could play Dark Souls in Minecraft with full stamina and shield mechanics ;)