Elemental Blockade is a skill located in the Destruction Staff (which can be found in the Weapon skill tree). Elemental Blockade is a morph of
Wall of Elements.
Elemental Blockade deals the following types of damage: Flame Damage, Frost Damage, Shock Damage. Which means that it gets buffed by the following blue champion point trees: Elemental Expert, Elf Born, Spell Erosion, Thaumaturge. Also the following red champion point trees protect against this skill: Elemental Defender, Thick Skinned.
ESO Skillbook