Consider that this skill gives almost as much armor as a shield, and more energy than most focus items, negating some of the drawbacks of other ash-holding spells.
Use Mighty Was Vorizun with Herald's Insignias to gain a +25 armor boost, for 85 AL overall.
Keep in mind that the ashes replace your weapon and focus so you lose their mods. If your weapon has a +15 energy bonus and you summon the ashes, you will get only a net +15 Energy max boost.
Some R/Rts might consider using this skill while trapping instead of the staff/wand + focus combo, because of the added armor that can help in some situations.
If the spirit Empowerment is in the area, you can get a major energy boost of 40 maximum energy
Keep in mind that if you have less than 30 energy and no +energy equipment when the spell ends, your energy will be sent below 0, which can prevent you from using most skills for a time. On the flip side, not only does the skill increase your max energy it also gives you that much energy as well, so casting with 5 energy will cause your energy to decrease by 5 and then increase by 30 so you will suddenly have 30 energy (again, assuming no weapon mods).