My view is tailored more towards the PvE side of things but if you feel your have helpfuly insight or input for a PvP idea fell free to post.
As it lies Spirit shell is regularly resulting in over 50% of a disc priests heals. If an encounter has any high damage output phase Spiritshell currently can soak/absorb a lot when coupled with Prayer of Healing(PoH).
I personally love the idea or concept behind spirit shell but I also can see how it has become something that game designers did not set out to create. Currently a healing discs rotation give or take a few smites for archangel and a few PW:S for rapture is PoH and Fiend/shell on CD if not in high damage taken areas as a raid CD.
I would like to suggest some possible solutions or at least ideas that could possibly be incorporated into the spirit shell design to improve its functionality (not just used with PoH spam) while still allowing the player feel like they are playing Disc.
There are two potential ideas that would allow Spiritshell be incorporated while still making other Disc spells feasible to use with Spiritshell.
Spiritshell functions as a toggle option for heals or healing similar to that or rogues blade flurry. Spiritshell healing would reduce all Direct heals by a % figure lets say 60% while buffing the healing of absorb affects. So Flash heal, greater heal, heal and penance get taxed while PW:S, Divine Agis (PoH) get an absorb buff lets say 30%
Missing Links: Whats stopping Discs staying in Spiritshell 100% of the time?
A mechanic would need to be developed to encourage Discs to heal out of Spiritshell.
Many features like this currently exist in game, hunter focus and the use of steady shot to regain it, warlocks and the use of spells outside demon form to generate power.
Tree form - SpiritShell, disperses your soul over raid members within 40yrds - absorbing (x amount of damage) amount of damage per attack/second/or base amount. Lasts for 20 seconds - 3 min CD
No longer functions as a shell effect instead as a cool down while applies the shell effect, possible even a channel for 3-5 seconds if an instant cast shell is not feasible.
Spiritshell becomes a passive build up effect. The best to explain this would be the trinket effect from the "Vial of the Sunwell". Healing power is collected or stored for each and every heal that the priest performs, at any point the priest can change to "Spiritshell" and spend this stored healing power on shields and absorbs. The more healing stored the stronger the absorbs. The ability would be a toggle ability with only specific abilities adding to the healing stored.
Links to item
If you believe you can improve on or have another suggestion for the functionality of this ability please post here. I'm sure even if this is not used the ideas garnished could help the devs with their next concept.
I would love to see some blues feedback if we can get some reasons why this hasn't worked (if these have been brainstormed before) or if some of the ideas posted may potentially work/not work.