Krittika is the third, ruled by the Sun, its symbol a razor or a flame, its deity Agni, god of fire. It's also the Pleiades — in the Vedic story the six mothers who raised the war god Kārttikeya, from whom the name comes. So Krittika is fire and blade, and also wet-nurse: burn off, cut away, then raise what remains.
Mechanically the Sun as ruler matters here: the Sun is illumination and purity, and fire is the tool of transformation. The character of this nakshatra is separation — pure from impure. Sacrificial fire consumes the offering and sends it up; kitchen fire turns raw into cooked; the razor takes off what should go. All three are one thing: it's through fire that something becomes usable.
Where you'll recognise it: you see what's wrong, you speak directly and accurately, you hold a standard for quality, you have no patience for murk or pretence, and there's a clarity about you that draws respect and a little fear. Running well, you're the best refiner: making things pure, pushing people to the level they should be at, cutting the useless. Stuck, you burn too hot — criticising everything, sharpness mistaken for honesty, burning away the very thing you meant to raise. Bharani before it carries; Rohini after it grows: only after the burning is the ground clean enough to plant.