I have an idea that would work nicely and imo adress 2 issues.
I like the current 'Shape of the Wild' slave spell in theory: higher mana regen, nice damage bonus, good atk (if meleeing is your thing), even a really fast movement speed buff. But its really impractical and hardly worth using atm. The problems I see with it are:
It gives mana regen (+5mana regen) with the same stacking as self buff 'Mask of the Hunter' (+4mana regen). But with JB(18)+WoN(8)+Mask(4) you hit the 30cap as is so as long as you have a JB the extra mana regen isnt necessary.
It has wolf form. While it does give you a movement speed buff that is a bit faster then Flight of the Eagles it limits you severly in two ways. 1) It makes it outdoor only so you cannot benefit from it in most of the zones you spend your time in. 2) Really any illusion for druids isnt worth clicking/casting since anytime you go into Shape of the Earthmother form it will just overwrite it/does not stack. So basically for anyone unfirmiliar with the two spells your giving up overcap FT for 2% to spell damage, slightly faster movement speed, atk, and having your self mana regen and movement speed buff only take up 1 buff slot instead of 2.
What if you stripped the movement speed from it, so it could be used indoor/outdoor. Change the mana regen to where instead of giving Mask of the Hunter stacking mana regen it gave the overcap mana regen that Earthmother gives. And then tack on any kind of benefits deemed necessary to balance druids into that spell (15% casting speed or whatever the solution is decieded to be).
This way you would have a viable illusion that worked in all zones, was worth the buff slot, wouldnt break from aoe damage to tack the changes onto and as a bonus the slave spell would be worth using.
Another plus I see to this is that at lower levels/tiers druids are pretty powerful/desired class as is. They have ports for all the tmaps being done in those tiers, their utility through buffs are more often not being replaced by bots at that point and their heals are adequate as is at those levels. So you'd be introducing a fix to a problem that really starts around the tier that slave spells can be obtained rather then giving earlier when the classes are pretty powerful/desired.
At any rate, even if its decieded that nothing will be done about the druid situation, I think the slave spell should be changed somehow. Even if you just made it a continuation of Mask of the Hunter by stripping the wolf form/movement speed part out of the buff and not adding anything else to it would make it much more useful in terms of zone compatibility and stacking with Shape of the Earthmother.