Melina may not be the only friendly NPC in Elden Ring, but she's certainly the most prominent, accompanying your character throughout their entire journey and serving as a catalyst for both the plot and almost all of the crucial mechanics. It's baffling, then, that someone would want to kill her – a feat normally only achievable in very, very specific circumstances in the game – but, as always, the Internet finds a way.
Using a bugged combination of a certain spell and a certain weapon, a Reddit user was able to set themselves on fire indefinitely, thus horribly immolating Melina when they summoned her. You're not meant to be able to move freely or attack when talking to Melina at one of her summon points, but the area of effect of the spell proved to be wide enough that they didn't actually have to, thus allowing them to stab their only friend in the back and kneecap the entire story of the game. (Or not, considering that she showed up just fine at a later summon point – apparently even FromSoft themselves didn't think of this possibility.)