Normal Eggwars: Debuffer - it just doesn't lose any use over different item types and is powerful in all of them. A weakness potion can let you take on full iron players with just leather gear with relative ease.
Speed Eggwars: MasterMine - The haste makes it really easy to break eggs and makes swords swing faster so you can combo easier. Also it is good across all item types which is a huge bonus and lasts for as long as you are alive.