This is an idea based solely on flowers only! However, suggestions with other plants would be fine. Plant based frames are strangely not present in this game (Saryn isn't anywhere near plant based). Any vegetation ideas can count. Here are some ideas for a whole kit but it's just to start.
The more flowers that are present on the field, the stronger Gaeo becomes. When he casts an ability, flowers are left behind around him or the target that it hits. When there are 3 flowers within 50m of him, he and his allies regenerate 3 hp per second. Each 3 flowers will increase this healing by 1. He alone gets 100 armor when he's standing still or aiming still while near flowers. Flowers decay after 30 seconds. 50 flowers can be on the field at once and will replace the old flowers if it exceeds this cap.
1st Ability: Bouncing Nightingale
Throw a Nightingale at the first opponent you see. The flower will put the enemy it hits to sleep and will bounce to the next nearest enemy. The sleep lasts indefinitely but will deal damage over time on the enemy until the enemy takes enough damage to wake up. Will leave behind a flower per bounce.
This ability scales with Power Strength. It increases the damage threshold before the enemy awakes and the damage over time.
Damage Threshold: 10/17/25/34% of the enemy's max HP.
Damage over Time: Deals 100/150/200/250 toxin damage per second over time until the enemy wakes up.
This ability scales with Ability Range. It increases the number of enemies it can bounce to and how far the enemy could be to bounce to.
Bounces: 3/4/5/6 times
Range: enemies must be within 3/5/7/10m for it to bounce
Cost: 25 Energy
2nd Ability: Rose of Thorns
Plant a rose where Gaeo stands. The rose grants Toxic Thorns to allies which adds toxin damage to allies' attacks within range. If enemies stand near the rose, the rose will burst after 3 seconds. Enemies hit will have their armor removed for 3 seconds and increases the toxin damage they take per second. The flower will burst every 3 seconds while enemies stand near the rose. Leaves flowers when an enemy is hit by the burst.
This ability scales with Power Strength. It increases the damage dealt to enemies from allies' Thorns effect and the increase in toxin damage enemies take.
Toxic Thorns Damage: Adds 60/80/100/120 toxin damage to ally attacks
Toxin Weakness: 5/7/10/14% per second; stacks indefinitely
This ability scales with Power Duration. It increases the time that the rose will last before it decays.
Duration: 7/10/13/16 seconds
This ability scales with Power Range. It increases the range of the buff and the burst.
Aura and Burst Range: 10/15/20/25m
Cost 50 Energy
3rd Ability: Tulip Mania
Create a tulip that will float on top of Gaeo's head. All allies within the tulip's presence will gain increased armor, increased healing and immunity to all toxin procs. Enemies in range will start to weaken as they feel fatigued but never enough to put them to sleep. Enemies that are asleep will have their damage threshold increased only while in the range of the tulip. Creates flowers every 5 seconds at where Gaeo stands.
This ability scales with Power Strength. It will increase the armor gained, the healing increase, the weaken amount and the damage threshold increase.
Armor: 100/150/200/250 armor
Healing Increase: Healing from all sources are increased by 10/15/20/25%
Damage Reduction: 70/80/90/100% to melee damage. 35/40/45/50% to ranged damage.
Threshold Increase: Adds 10/15/25/40% to the Damage Threshold (capped at 100%)
This ability scales with Power Duration. It will increase the duration of the tulip.
Duration: 6/8/10/12 seconds
This ability scales with Power Range. It increases the aura range.
Cost: 75 Energy
Blow a fluffy dandelion at enemies. Enemies hit are infected with dandelions and will start to leave behind flower petals. Slowly, the enemies get transformed into dandelions when they "die". Enemies that asleep will instantly be transformed into a dandelion. Allies that walk over the dandelions will recover health and instantly kills the enemy who was put to sleep. Allies will also gain increased damage with weapons for a brief amount of time. Enemies that allies walk over will leave flowers
This ability scales with Power Strength. It increases the healing and the damage buff.
Healing: 40/50/75/80%% of allies max HP
Damage Buff: 50/55/60/70%
This ability scales with Power Duration. It increases the duration of the transformation if they weren't transformed from dying and the buff duration.
Transformation: 10/15/20/25 seconds
Buff: 5/8/12/17 seconds (refreshed when walking over another Dandelion)
This ability scales with Power Range. It increases the range of the initial blow.
Range: 5/8/10/15m in a 45 degree cone in front of him.
Cost: 100 Energy