[Champion Concept] Cora, the Gift of Nature.
Cora is a tanky animal-whisperer who I would play as either a toplaner or a support, but she could be played as a jungler too.
She looks slightly elvish, with some vines and green line tattoos around her limbs. Give her an ethereal look in her eyes, and make her hair long (maybe blonde).
Let's go to her kit. She's mana-based.
Passive: Soulsight Cora stares right into the hearts of people, granting her advantages when working together or working against someone. The longer she stays around a champion/friendly monster, the more powerful the effects of her spells get. The longer she stays around enemy champions, the less damage she takes from them.
Cora's spirit animal has the same life regeneration as Cora, and will restore a health potion worth of health when Cora chugs one.
When Cora dies, her spirit animal will go berserk and start attacking the nearest enemy unit (priority on champs) until it dies (it starts to decay away by itself)
Q - Adaptive Ray Cora charges up and shoots a projectile (like a Xerath Q, but with a projectile) the range and the speed of the projectile depends on the length of the charge. The projectile heals allied champions and monsters slightly and gives them a slight AS buff, but hurts and decreases the AS of enemies instead. This would look like a bunch of vines made of light, they would switch color to green and red depending on what they pass through, indicating which effect happened.
W - Soothe Cora uses a slight amount of her health and mana to heal her spirit animal for quite a reasonable amount, give it a short MS burst, and make its next AA stun the enemy. The AA stun has no timer, so you could wait a minute before using it. If you use two W stuns in rapid succession, the second stun will last only 25% of the standard stun time.
E - Intrigue Passive: Enemies all get a slight MS debuff around Cora (Low, maybe 2-4-6-8-10MS or 4-8-12-16-20MS) Active: Cora deals a large chunk of true damage to a monster, taking it over if it is slain by this ability. Intrigue can not be used again until the monster is dead. The monster's stats scale with Cora's stats. The monster is controlled with the E button. Does not work on drake and baron.
Cora's spirit animal can move independently from Cora, which means that there is NO RANGE LIMIT.
R - The Rise Cora buffs her currently controlled spirit animal with extra HP, extra AS, extra resistances, extra MS and extra damage. She also gives every allied unit around her a slight shield, including things like ZZ'rot voidlings, creeps, allied champions, friendly monsters and increases their AD and AP by a slight amount. This ability can not be used if there is currently no spirit animal.
How to play her: She's kind of similar to a Lulu and maybe a bit like Maokai too. She's supposed to stay around and annoy enemy champions, and works with her own spirit animal, buffs, and debuffs to do so. If you play her as a support, try to line up your Q to buff your ADC and hurt the enemy duo at the same time. Ask your jungler to help with Krugs or Gromp if possible, because the spirit animal will be very useful in the lane. Don't be rash with your spirit animal, because your E has a long cooldown (Like a Quinn W) and you're supposed to sustain your animal back up. You're not supposed to think of the animal as disposable poke, but as a part of the team.
In top-lane, you should try to teamfight ASAP. You don't have very many damaging skills, so toplane fights will most likely be lost unless you use your spirit animal very well. Although she doesn't have dashes, she has her AoE slow, so you could consider going smite TP to get the most out of your E true damage.
As a jungler, you're mostly there to buff your teammates. You don't have a lot of reliable CC, but you could use your W on your spirit animal to get a quick stun off. Your R can be really useful to prevent AoE wombo combos, as it's essentially a more powerful locket, use it well!
You also have lots of map pressure because of your spirit animal, use it well!