Not Updated For Current Season
The masteries shown here are not yet updated for the current season, the guide author needs to set up the new masteries. As such, they will be different than the masteries you see in-game.
Start /w Doran's Blade + HP pot, try to kill as many minions to put yourself ahead in game. Well once you get a feel for Cait, she gets op :D
Setting traps in bushes gives you brief sight of the surrounding so make use of that.
Doran's Blade+HP pot -> Boots -> Berserker's Greaves ^2 hp pots if needed -> BF Blade -> Black Cleaver -> zeal -> BF Blade -> Phantom Dancer -> sell Doran's Blade for Vampric Scepter -> The Bloothirster -> BF Blade -> Infinity Edge -> Last Whisper or Madred's Bloodrazor.
Once you get 1 bf blade Farm minions, Line them up and use Q nd kill off the mage creeps and repeat. My end games, I killed over 270 creeps nd forced surrenders.
Squishy hp? yea but the dmg output w/ vamp I find can make up for it.
If you ever go to super late games(1hr+), I suggest 3 phantom Dancers, 1 Bloodthirster, and 2 infinity Edges. ull tear through 4k hp in an instant.