Originally Posted by
Themi
OK, I think you are mixing some things together here. I'll try to clear it up.
1. If you have the t21 4pc, you are running aftershock for single target. It does not matter which legendaries you have or do not have. You do NOT however play the gambling rotation and still cast earthshock at near max maelstrom. You only start casting it at lower maelstrom levels once you have the shoes and gloves.
2. Generally you want to take echo of the elements. HOWEVER some gear configurations may see storm ele as higher dps. A quick sim of your character reveals that it is indeed the case with your current gear. That it because you have very low Mastery lvls while having tons of crit and haste. The problem is that storm ele is alway fight length dependent. If you are in doubt, echo might still be the better option, as the difference is low and it is more reliable.
For Mythic+ you'd want magma totem in most weeks/instances. Echo/Stormele(Again, dpeneding on gear) might be better in tyrannical weeks in instances with low trash mob count.
3. This changes slightly if you use the talent ring. Either because you have nothing else or because it is good in mythic+. In a raid scenario you mostly do not want to wear the talent ring if avoidable. In case you use it, you automatically gain echo, thus making storm ele the single target choice and liquid magma the ae(mythic+) choice.
TL;DR: Skill aftershock with t21, storm ele for st damage, lm for ae damage