Shield Bearer (5e Feat)
From D&D Wiki
Prerequisites: Strength or Dexterity 13 or higher.
You are a master of the shield! You bear the burden of the shield so that your fellows can stay out of harms way!
-- Shield Wall: Whenever allies stands near your sides and/or back but not your front they are given half cover for as long as they stand there.
-- Hold Fast: As a bonus action any allies gaining the benefit of your Shield Wall now have three quarters cover until the end of your next turn. While doing this your speed becomes zero.
-- Rally: Twice per long rest as a action you can give your allies within 20ft of you advantage on dexterity or strength(choose one) checks and saving throws but you reduce your speed by half and you have disadvantage on dexterity or strength checks and saving throws(same as your choice). This lasts for two rounds of combat but you can end this early as a bonus action.