Is your Grey Feather set fully heated?

Without heart trinkets, you're sitting at 18 pips if max heated Grey Feather, but 16 if they're both under Level 5. That might be just low enough for a one hit kill.

Should've mentioned that heat. I don't know exactly how much defence you're missing from not having full heat, but if it's anything like weapons you'd be missing 25%.

Gray Feather set at full heat has 125 normal and 150 elemental defence.

Weapns rise exponentially, so a level 4 set wouldn't have mentionably more defence than a level 1 set.

At a 25% reduction, this leaves you at 93.75 normal and 112.5 elemental. Notice that 93.75 is below Lockdown's fixed defence of 100 for all damage types, so you effectively had no normal defence at all and only 12.5 elemental. This is kind of like if you were wearing Vog Cub cap and Radiant Silvermail, with a max elemental UV on both pieces: no defence to anything except that tiny amount of elemental.

You also had only 13 health, assuming you were playing as Striker, since you had no pentas. 13 pips = 520.

However, according to my numbers, that should still not be enough to kill you unless you were poisoned or deathmarked or something else that would reduce your natural 100 defence.

Just so we're both clear:

Are you sure you were not deathmarked? Deathmark totally eliminates your defence.

subtle feyi ego stroke