Samira runs on a literal style mechanic. Daredevil Impulse raises a combo grade each time she lands an attack or ability that differs from the one before it, so she is rewarded for alternating gunshots, sword swings, and dashes instead of spamming one move. Her melee-range attacks add bonus magic damage, and she can dash onto enemies held in place by immobilizing effects, which is why hook-and-stun supports in the bot lane suit her so well.
Flair changes with distance: at range it fires a shot, and up close it becomes a blade swing. Cast during Wild Rush, it hits everything along the path of her dash. Wild Rush drives her aggression. It is a dash through enemies (structures count too) that boosts attack speed and, most importantly, resets its own cooldown whenever she gets a champion kill, which makes the chain resets behind her strongest fights possible. Blade Whirl is her defensive tool: a spinning slash that damages nearby enemies and destroys incoming enemy missiles, letting her stand in skillshot crossfire that would kill most other marksmen.
Inferno Trigger is where the whole rhythm pays off. It sprays a barrage of shots at every enemy around her. Most marksman ultimates ask for distance, but this one asks her to dive into the middle of the enemy team. Paired with Wild Rush resets, it creates the well-known pentakill cleanup loop: kill, reset, dash, fire again.
Samira is a Marksman/Assassin hybrid built for ADCs who find back-line kiting too passive. She gives up the safety of range in exchange for close-quarters damage, does her best work against grouped enemies, and relies on allied crowd control and tight combo execution. Once the resets dry up, so does her damage.