Circle of the Guardian

It is said that this Circle is not a big conglomeration of druids, nor is it even set in a physical place.
This Circle is a gift, or maybe a destiny, one That is believed to be laid upon special souls who, may be for being chosen or a bloodline, it truly doesn't matter, for you are eternally bound to nature, and you are it's protector.

Visage Of Oberon

When you choose this circle at 2nd level, you learn one additional druid cantrip of your choice. This cantrip doesn’t count against the number of druid cantrips you know. 

Moreover, you lose the ability to transform into animals of any kind, instead you gain Visage of Oberon, a form that nature chose for the ultimate Druidic Evolution.

Visage Of Oberon:

As you Wildshape, you forget all of the other beast you can turn into, but you can now transform into a sacred beast, changing the way you look (players choice), and be able to spellcast from this form

You are still considered medium size (DM choice)

Your AC increases by 5. You gain the ability to cast 2 cantrips at once only if you begin your action with a cantrip. You gain an additional damage on your spells and cantrips using your Wisdom modifier. You gain a bonus + 5 to any CON saving throw that involves concentration.

You gain a flight speed double your speed on foot. (level 8)

One Wildshape charge is expended upon use.

Natural Protection

Starting at 3rd level, you can use a reaction to make nature protect an ally, this could also be yourself.

The target is shielded by whats around them (for example, in a forest setting, some roots may sprout from the ground to protect someone, its up to your imagination and the dms discretion) and lowers the damage that they would have taken, this damage negation is calculated by rolling a d6 + Druid level + Wisdom modifier.This die increases to a d8 at 8th level, d10 at 11th, and a d12 at 14th.

If the shield succeds in meeting the damage that the attack made, the creature protected by the shield takes no damage, but if it fails, the creature takes half damage.

You can use this reaction using your Proficiency bonus, as much times as that number

At level 14, you can instead use it as an action.

Thorn Grapple

Your Thorn Whip cantrip gets improved.

As an action, you can use this cantrip to propel yourself forward to the point  that you launched the vine.
The range of this ability is 30 feet.

Nature's Wrath

Whenever you protect an allied or yourself with this shield, if a target breaks it, it takes damage depending on what the shield is made out of.

The damage is 2d6 at 6th level, 4d6 at 10th level, 6d6 at 14th and 8d6 at 18th

Nature’s Ward

When you reach 10th level, you can’t be charmed or frightened by elementals or fey, and you are immune to poison and disease.

Also, when you cast your natural protection, you may choose to waste your action on your next turn to make the wall of nature 15 feet wide instead of the normal 5, giving you a wider protection area, but the damage done byh the shield when it breaks remains the same.

Offensive Defense

When you reach 14th level, you gain the charge feat, and i get improved.

When you use your action to Dash, you can use a bonus action to make one melee weapon attack or to shove a creature, if you have one hand free, you hit the target with the shield, and do the respective damage of Natures Wrath, If you move at least 10 feet in a straight line immediately before taking this bonus action, you either gain a +5 bonus to the attack’s damage roll or push the target up to 10 feet away from you (if you chose to shove and you succeed).