I wrote this as a late addition to Robstar Week 2016. The prompt was PTSD and I decided to do a little follow up of Haunted. Robin suffered a lot in that episode, but my headcanon is that Starfire has more scars than the others may realize from that night.
The first time lightning struck near the Tower, she had no idea what it was. It petrified her. Robin found her huddled tightly under her rosy blankets, shrieking when the lightning flashed and breathing heavily as the thunder boomed. He rubbed her back and reassured her that the storm was simply nature's way of releasing electricity back to Earth. The alien queried about its dangers. He told her she had nothing to fear as long as she did not stray high in the sky or alone in an open field. Although with her physical strength, she was the least likely of the Titans to be injured by an energy blast besides Cyborg.
After that night, the storms almost brought a lingering calm to her. The beauty of the quick flashes and pounding rain entranced her. Water contrasted her own fiery powers, yet she gravitated towards the light amidst the dark for an inexplicable reason.
Though the brothers who created the force of nature were immature to a fault at first, they proved to be a welcome ally. Starfire did not have to fear their show of power each time they orchestrated a performance.
When Raven's suppressed powers hunted the team down, the worry over finding her missing friends cut into her admiration of the storm. She feared capture more than she did a surge of lightning.
Her fear soon returned and clung to her like a poltergeist. The thunder pounded her eardrums, the harshness of Robin's yelling cutting deeper than the bruises he left on her arm. Fresh wounds exposed when he abandoned her on his hallucinogen-induced search. Lightning streaked across her tear stricken face as she carried the unconscious leader back to the tower after he bared a birdarang at them. Deafening roars filled the halls as she raced to save her best friend from the torments of his own mind.
Since then, stormy nights brought nothing but horrific nightmares. If she were lucky, Robin would only get angry by that same empty field in the woods. Most times, Slade beat him into a pulp before her eyes, sending her into a raging fury. Any attempt to strike out at the madman would be in vain. At the flash of lightning, he disappeared. Gone without a trace. His cruel voice taunted her from an indiscernible source.
You let poor Robin die, girl. You simply couldn't save him. How could you? You can't even save yourself.
Walls enclosed around her, crushing into her until she could hardly move. Robin's sudden screams sent a jolt through her. She tried to wiggle out of the tight crevice, shooting eyebolts through the stone, anything to reach him, but to no avail. A blot of dark orange appeared in her peripheral and her eyes narrowed in on her target.
Slade formed out of the darkness, stepping closer to her. Combat boots sounded over the rumble of the stone walls. The man lifted up a groaning Robin in one arm. The boy's outfit torn and red splattered across his drained face. Starfire scraped her arm against the edge of the crevice and managed to free only the limb to reach for her best friend. Her starbolt energy flickered and died on her palm.
Slade's single eye narrowed as if sneering at her. His other hand carried a detonator device. The thumb pressed the trigger. An eerie orange glow erupted across Robin's skin. Starfire recognized it as the probes that once threatened to tear her body apart from the inside out. Robin thrashed in Slade's grasp, clutching tightly at his stomach.
"Starfire! Please, help!" he pleaded through strangled gasps.
"Robin, I cannot reach you!" Her eyes began to water. Breathing shuddered, though not from the weight of the pressing walls. She directed her attention to the masked villain and growled. "Release him or I will rip you apart!"
"Considering that you can't even touch me, I doubt that you'll be able to fulfill your promise," he replied coolly. "But, if you insist, your wish is my command."
The floor uncoiled between them. Starfire strained to peer down through the new opening. The basement appeared, full of scattered case files and chittering rats with red eyes flooded the floor, piling atop one another. The lights flickered ominously and several cracked Slade masks lined the walls. Starfire's ears could make out the villain's cackling pouring out from every mask.
In a moment that lasted for eternity, Slade tossed the thrashing Robin forward into the pit below. He found her eyes one final time.
"Robin! Robin, no!" she shrieked.
A dying scream was the only response.
The walls dug into her skin and choked the breath out of her. Her vision blurred, orange and black the only colors she could make out.
She couldn't breathe.
Her head spun despite being unable to move.
She fell and her eyes opened.
Startled, Starfire sat up. Breathing heavily, she allowed her eyes to dart around. The alien was in her room, the pattering sound of heavy rain the only sound filling the space.
Slade was nowhere to be seen. And neither was Robin.
He is sleeping safely. He is sleeping in his room as he always is, she repeated to herself. This mantra went on for several minutes until she could truly believe it.
Gripping a handful of hair tiredly, she fell back onto her disheveled sheets. It was only another nightmare, no doubt induced by the stormy weather.
She truly loved rain, but that night of Slade's supposed return left her with fitful nights of sleep at best on nights like this. Even though she never verbally confirmed it, Starfire had no doubt that Robin suffered from the same affliction. In the morning, they would wordlessly share hot cocoa and hold each other close on the couch.
The storm may not have washed away their presence, but it never failed to fell even the strongest of oaks in its wake.