Ion Fortuna's approach to fire. Spoilers through The Night Lords (ROM3) or the anime arc of the same name.
The old stories said that he should be afraid of fire. It was the weapon that the scions of the Church had used against their mythical anathema for centuries. Even if the Methuselah were beyond those superstitions, old habits were hard to break.
After his string of accidental burns, Ion Fortuna had finally learned to simply avoid it. Sister Esther was too tactful to reproach him, but he could feel the concern radiating from her small frame as she bandaged up his hand for the umpteenth time. He owed her too much to cause her undue worry, even if she was a Terran, so he kept himself away from the flickering flames but still failed miserably at not thinking about the past.
The Empress' rules meant that there were few instances where nobles of the Empire had to fight, but most in their long lives chose to hone their natural abilities anyway, if only as a hobby with which to pass the centuries. Ion himself had some training with sword and dagger, though he never deluded himself into thinking that he'd last for more than a few seconds against a real threat. It was as if adolescence had returned to exact extended vengeance for having been robbed of his mortality early - his knees and elbows always felt like they were strung together by rubber bands.
Radu, on the other hand, had a talent for it, and ever since they'd become partners, Ion had gotten into the habit of letting Radu handle all the physical conflicts for him. It was probably unbefitting a noble of his rank and might be taken as cowardice in some circles, but Ion could never bring himself to care.
For Ion the transition had been slow. Never a particularly early riser, he'd become more and more lethargic during the night, and slowly found the glare of the sun too bright to bear. Before he knew it he was staring at the mirror, into the eyes of the face he would wear for the rest of his life. Three, five, ten years he remained the same, and watched Radu age.
The genes that dictated the transformation varied from person to person, and even among the ranks of the noble houses of the Empire, no one was certain when exactly they would change. There were some who never did, and walked in the sun for their short mortal lives. All Ion could do was wait.
Until one morning, when his friend came to him with a gentle, secretive smile and said that there was something he wanted Ion to see. Feeling all of twelve years old and about to run afoul of his grandmother, he followed Radu outside, fireflies of midsummer drifting beneath the starry dome of day.
They walked to a disused fountain hidden amidst a stand of maples, a secret hideout they had used for years as children. Like a sage imparting hidden wisdom, Radu settled gracefully on the edge of the fountain and held out an empty hand.
Ion watched the flame flicker into life, a gentle blue radiance hovering a half-inch above the center of Radu's palm. Hesitantly, he reached out for the fire. It tickled his fingers and licked up the side of his wrist, but it didn't burn.
Relief flooded through Ion, an honest feeling of joy that had little to do with not getting singed. They wouldn't have forever - not even the Methuselah could claim that - but that morning marked the beginning of some measure of eternity that he wouldn't have to spend alone.
Flash forward some dozens of years, and he watched Radu fight in earnest, gentle candlelight roaring into gouts of azure flame as his friend drove back the insolent Terrans. The armored shells of their metal toys melted under the touch of the blaze that trailed elegant arcs through the air and licked at its prey with a life of its own.
Ion knew he should go help, draw his woefully inadequate shortsword and at least make an attempt to not embarrass his name. Instead he stood watching, mesmerized by the dazzling display of power and the instinctive thrill of danger that called to the not-quite-tamed things of claws and teeth within. He watched, because it was a side of his tovarich that he was so rarely able to see.
Unlike Ion himself, Radu was so calm, so unruffled most of the time, and no matter what tricks Ion pulled he always failed to provoke any kind of an interesting reaction. It was woefully unfair, since Radu didn't need to expend any effort of his own to witness Ion turning all the colors of the rainbow on a regular basis. The only time Ion got to see Radu's calm demeanor break was during combat, cold rage directed at the interlopers who dared threaten the welfare of himself and his friends, or when he was excited about some bizarre and wonderful novelty.
When he ranted about the politics of the empress whose pacifism - weakness - prevented them from eradicating the threat once and for all.
Staring into the tame blaze in the fireplace that nevertheless burned, Ion wished he'd listened.