For me, the electric attunement-scepter, specifically (arc lightning)1 and (lightning strike)2 do the most damage against single target boss encounters. On the scepter, fire is good for adding a burn or for aoe damage. Though I switched to other attunements when recast timers were down or to get boons- fury (+20% crit), might(+dmg), toughness. I also get a temp boon (+ might for fire; +toughness for earth) by casting the heal-elemental harmony in the corresponding attunement. I am learning more and more that you really have to work hard as an ele to output damage(if that’s how you want to play) by stacking boons like might through attunement switching and combo finishers.
