Here is a modified mock-up for what I imagined the Keeper of the Grove could be:
Keeper of the Grove Modified Mock up
Keystone: Dream Surge
Each Force of Nature grants 1 charge of Dream Burst, causing your next Nature or Astral spell to explode on the target, dealing Nature damage to nearby enemies. Damage reduced above 5 targets.
Grove Guardians causes your next targeted heal to create 2 Dream Petals near the target, healing up to 3 nearby allies. Stacks up to 5 charges.
Capstone: Harmony of the Grove
Each of your treants (Force of Nature and Grove Guardians) increases damage your spells deal by 3% and healing done by 3% while active. Treants spells benefit from your Mastery and prefers to casts on targets with Dots/Hots on them.
Middle Column: Dream Surge mechanics
Expansiveness
Your maximum mana is increased by 5%. Your leech is increased by 5%.
Cenarius’ Might
Every 3 casts of Starsurge or Starfall summons a Force of Nature treant.
Every 3 casts of Swiftmend summons a Grove Guardian treant.
Convoke the Spirit summons a Force of Nature and a Grove Guardian treants immediately.
Power of the Dream
Force of Nature grants an additional stack of Dream Burst.
Healing spells cast with Dream Surge generates an additional Dream Petal.
Control of the Dream
Force of Nature now has 2 Charges.
Dream Petals now only triggered automatically whenever a nearby ally falls under 35% health. You may have up to 10 Dream Petals at the same time.
Left Column: Treant Utilities/Functions
Treants of the Wild
Your treants cast Adaptive Swarm on your target when summoned.
Power of Nature
Your Force of Nature treants no longer taunt and now casts Wrath instead of melee attacking.
Your Grove Guardians increase the healing of your Regrowth, Efflorescence and Lifebloom by 5% while active.
Durability of Nature
Your Force of Nature treants have 50% increased health, When they die, they spawn a Wild Mushroom.
Your Grove Guardians’ Nourish and Swiftmend spell also apply a minor Cenarion Ward that heals the target over 8 sec the next time they take damage.
Bounteous Bloom
Your Force of Nature Treants generate 3 Astral Power every 2 sec.
Your Grove Guardians’ healing is increased by 20%.
Early Spring
Force of Nature cooldown reduced by 10 seconds.
Grove Guardian cooldown reduced by 3 seconds.
Right Column:
Protective Growth
While your Regrowth is on you, reduce all damage you take by 8%.
Grove’s Inspiration
Nature damage increased by 10%
Regrowth, Wild Growth and Swiftmend healing increased by 6%
Persistent Enchantments
Orbital Strike applies Stellar Flare for 6 additional seconds and Primordial Arcanic Pulsar grants Celestial Alignment for 2 additional seconds.
Reforestation grants Tree of Life for 2 additional seconds.
Blooming Infusion
Every Regrowth you cast reduces the cast time of your next Wrath, Rebirth or Entangling Roots by 20% and increases its damage by 20%. Stacks up to 5 times.
Every Starsurge or Starfall you cast reduces the cast time of your next Regrowth, Wild Growth, Rebirth or Entangling Roots by 20%. Stacks up to 5 times