This is a simple mod that I have made that implements Super Smash Bros style knockback to Minecraft! This works against players in PVP and on both vanilla and modded mobs!
Like Super Smash Bros., the knockback that you takes is determined by the percent you have! Percents are determined by testing to see how much health the player or mob has lost, so it works better if the player has a larger amount of health (such as through a health boost command). When on over 100%, the player will also have smoke particles surrounding them and as a result, will take much more knockback than before!
This feature can be enabled or disabled through the command /togglepercentknockback
