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.
This is my personal Cassiopeia build, this works best for me. Try it!
2 Crowd Control spells
Ultimate is a life saver. For everyone.
Infinite mana late game.
Slow spells, hard to aim.
Squishy early game.
Cassiopeia is a very Strong character with poison abilities. Her Twin Fang (E) ability STACKS with teemo's mushrooms and auto attacks. Her Noxious Blast (Q) is the strongest early spell and a low cool down of 3 seconds. Miasma (W) and Petrifying Gaze (R) are Cassiopeia's bread skills, setting up for others.
Cassiopeia is a Damage Over Time (DoT) character with low cool down spells. She is a decent chaser with her slow, self haste and stun spells. She is squishy early game but grows strong heavily later. Cassiopeia can deal a strong amount of damage to a team of 5 quickly.
Ganks: Flash(D/F) >> Petrifying Gaze >> Miasma >> Twin Fang >> Noxious Blast >> Twin Fang.
Team Fights: Petrifying Gaze >> Miasma >> Noxious Blast >> Twin Fang >> (repeat) Miasma.
IT IS VERY TEMPTING TO HARASS, but that will get you killed because you deal DoT and has full potential when not threatened by income damage. You are likely to kill a champion with your spells even after you die due to poison.
Only few things to remember:
LAST HIT: Attack the minions only when they're at low health causing you to gain the extra 25-35 gold.
STAY SAFE: Don't put yourself in danger, "curiosity killed the cat." as in do not check bushes just to see what's there. Dodge income attacks, try to not get hit and/or targeted.
BE A LEADER: Remember to remind your team about the Dragons global 240 gold, baron, golem/lizard buffs, Missing In Actions (MIA) and ganks.
CHECK OUT MY OTHER BUILDS!!
AP TRISTANA: http://www.mobafire.com/league-of-legends/build/tristanasonehitwonder-ap-7154