Smell of the king

if you kill the ender dragon you just get it's egg and the permission to go to the end city. So i think if you kill the ender dragon you will get a potion effect : " Smell of the King " it will scare almost every mob in 1 or more chunk radious expect villagers, iron golems, and wither. You can even get this effect from the wither. A new block the spreader is like dispenser could drop items and water your crops if water inside, whit dragon breath compared with water in crafting table you can spread this smell to other mobs and you. for exemple you can spread this to villagers to defend them from zomnies the elfect will last longer than all potions f.e.: 3 real time day