Thanks for the feed back so far. Astral Spirit perhaps should either have overload or cost 6 I agree in hind sight in addition to breaking the game as a whole :/. Crackle is essentially the only combo that really benefits form Nobundo but perhaps its rather strong as a +3 spell damage essentially. I do like removing the random damage factor however. Additionally pardon my typos if that bothers you.
I've also pondered the possibility of adding secrets to the shaman class since they would be the only class to price secrets at 0 casting mana with overload as a cost to make the secrets neither useless nor overpowered. I thought grounding totem would initially be good but spell bender is far too similar so the next best option was to use the iconic shaman shields which for some random reason were absent from hearthstone (along with purge since 4 secrets are at minimum needed.)
-[Changed/Altered to 3 spell damage to attacker]
Lightning shield: Great for protecting totems and trading, you pay a delayed 2 mana for essentially a defensive abusive sergeant / fire elemental ability without a body.
Water shield: Effecting mana pools seam appropriate and with tesla coil being a thing, perhaps and alternate method to transfer overload would be ideal. Easy to play around but at least causes your opponent to use a low mana spell before a large one (essentially blocks mind control or pyro blast).
Earth Shield: Similar to the mage's ice barrier, the shield provided is at half strength and will often negate low attack creatures for a small damage negation on the other ability part. However the niche of potentially blocking a large minion attack makes the ability unique. May cause confusion with lightning shield.
Purge: An earth shock you can't really control but with the benefit of potentially hitting for 2 damage instead of 1 for the 2 mana. This can stop charge wombo combos but is essentially worthless against defender of argus or any throw away minion. The damage may be too strong, but if played early it causes the shaman to completely skip their following turn.