Rucus is a pain if you're the only one attacking him but if you have movement speed, use explosive flask and use weightless to evade him then its easier to counter as long as you move like a bat out of hell; only this one has a potion launcher.
Unlike certain champions, Pip's damage is the same from wherever you fire from or where you hit. Remember to keep distance and practice getting used to the arc of his attacks.
Get Haven and Life Rip for sustain, and take Rogue's Gambit for mobility or Artful Dodger for even more sustain. Also keep in mind Lex's Retribution; always be prepared for an ambush.