For starts, Oberon is not a plant warframe just because Hallowed ground has grass effects. They weren’t even there to begin with, and contribute nothing to the abilities overall effects. That being said, onto the actual concept.
Name wise I decided to call this frame Chloros. I’m sure there’s better names out there but this is a place holder. To give this frame a back story I actually took inspiration from something we have in reality. On earth we have a sort of fail safe bunker that holds seeds of every plant in case something wipes one of them out. I find the concept of Chloros being designed to protect this in warframe to be a fitting story.
Stat wise I imagine them having average shield, high health, above average armor, average energy and average speed. I can’t come up with exact numbers as I'm not sure what would make them effective but not game breaking.
Before I go into actual abilities I wanted to state that my goal was to make this a snowball frame as it fits the plant theme. Plants are known for growing and so I think this frame should reflect that aspect.
Chloros’ passive is that every kill grants a percentage of their growth. Each percent grants Chloros 10 extra health. Additionally abilities grow stronger based on this value. It maxes out at 100% so up to 1000 extra health.
Chloros’ first ability is Vine Skewer. This sends a vine from the ground and strikes directly forwards to hit enemies for puncture damage. Enemies killed drop “Glucose” orbs that restore 10% health and energy to any warframe that picks it up. For every 10% growth another vine is sent forward, increasing the attacks area of effect. Maxing out at 11 vines at 100% Strength scales the attacks damage and orb restoration, and range scales how far it reaches.
Chloros’ second ability is Harvest. This has Chloros cycle between four plants they can place down. Additionally there’s an effect when vine Skewer is used.
Briar Patch creates Thorned vines that slow enemies and inflict slash damage when they walk through. Using Vine Skewer on enemies that are in Briar Patch makes them drop two orbs. Percentage increases the area this ability covers. It also is affected by range, strength and duration mods.
Cactus Blast grows a cactus that draws aggro from enemies. It takes damage absorbed from enemies and releases it into a radial burst of damage. Striking it with Vine Skewer will cause it to release a burst preemptively without losing stored damage. Growth Percentage increases the multiplier given to absorbed damage. By default it is 1x but gains 0.1x for every percentage up to 11x. Affected by range, duration and strength (adjusts damage dealt by default that is added to absorbed damage)
Pitcher Mortar creates a plant that lobs Corrosive bombs at distant enemies. These bombs leave puddles that linger for a few seconds dealing corrosive damage. Striking an enemy in a puddle with Vine Skewer will cause them to release a burst of corrosive damage. Growth percentage increases the Pitcher Mortars Fire rate. Scales with range, strength and duration (range and duration do not affect puddles).
Sun Dew grabs enemies and groups them together, dealing viral damage. Hitting a bound enemy with Vine Skewer will cause a burst of viral damage. Growth percentage increases it’s grabbing range. Scales with range, duration and strength.
Chloros’ Third ability, Woodland Guard, is a simple damage reduction power. It only affects Chloros and gains benefits by walking through harvests plants, destroying the plant and applying the affect for its remaining duration. Briar Patch causes attackers to take slash damage. Cactus Blast causes Chloros to periodically release a burst of damage. Pitcher Mortar causes Chloros to leave a trail of Corrosive fluids. Sun Dew grants viral damage to Melee Strikes. Growth percentage boosts Woodland Guards duration. Mods boost its damage reduction and duration.
Chloros’ Last ability is Photosynthesis. Grants regeneration to Chloros and their teammates as well as buffs other abilities based on Chloros’ growth percentage. Additionally abilities gain heat and radiation damage and procs.
Vine Skewer gains damage and doubles drops.
Harvest gains increases to all plant damage.
Woodland guard gives a percentage of Chloros’ damage reduction to all teammates.