Welcome back, Mobafire! I am Demonlordraiden, author of Lulu, the Fae Machinegun and I welcome you to my newest build!

Firstly, a short video to describe this build.
Play Video
Above was Samuel L. Jackson, one of the best actors ever to walk the earth. The movie, Snakes on a Plane. While this quote was OBVIOUSLY not written about Cassiopeia or this build, it fits very well.

"I have had it with these mother f*cking snakes, on this mother f*cking plane."

Now, if you would, replace "these" with "this," "snakes" with "snake," and "on this mother f*cking plane" to "in this mother f*cking lane."

That's right, "I have had it with this mother f*cking snake, in this mother f*cking lane." Describes this build well.

Cassiopeia is a very powerful Damage Over Time Champion, utilizing Noxious Blast, Miasma, and Ignite to damage enemies while out of sight, but not out of mind.

Pro:

Damage Over Time out the Roof!!
Rarely Mana Hungry
Very Low Cooldowns

Con:

Squishy
Very Low Crowd Control

Like any other champion, Cassiopeia needs Pre-Game Preparation to be truly useful. Unlink the previous champion I built ( Lulu), Cassiopeia has very few viable builds. Ability Power is where it's at.

Why?

Her Damage Over Time scales off of her Ability Power.

Enough Said.

Cassiopeia's Mastery Page is a standard Ability Power build, with some extra Utility.

Summoner's Wrath is just amazing here. Why? It buffs Ignite, and Ignite equals more Damage Over Time.

Mental Force effects my Ability Power, increasing my Poison Damage. See a pattern here?

Sorcery helps with the almost nonexistent Cooldowns, but also allows for Arcane Knowledge .

Arcane Knowledge increases Cassiopeia's Magic Penetration, leading to, wait for it...MORE POISON DAMAGE.

Havoc is...well...similar to above. Damage works with Poison.

Blast ...well...do I even need to explain this?

Archmage ...

Executioner is greatness because of two reasons. One, it helps on enemy Champions. Two, it helps on Monsters.

I have no Defense Masteries (again).

Expanded Mind makes it where I'm less likely to be Mana Hungry.

Improved Recall helps keep zero deaths, as we can teleport out if there is a problem.

Meditation is nice during prolonged fights to help with Noxious Blast's constant spamming.

Scout helps keep the jungle secure.

Runic Affinity is a MUST HAVE for any Jungler, including Cassiopeia.

Cassiopeia has very similar runes to a normal Brand or Veigar, going for high Ability Power.

Greater Glyph of Ability Power increases Ability Power. Why would we do that? If you answered with, "to deal more Poison Damage," you were right!

Greater Mark of Ability Power...should I explain, or make you guess? -.-

Greater Quintessence of Gold helps with Early Game Items.

Greater Quintessence of Scaling Ability Power is for what? What? WHAT!!??

...I'm sorry for yelling :( Can you forgive me? Thank you friend :)

Greater Seal of Gold is just like the Greater Quintessence of Gold.

Ignite is a MUST HAVE. MUST...HAVE...Extra Damage Over Time is a godsend for Cassiopeia.

Flash is just perfect on Cassiopeia, since, aside from an effect on Noxious Blast (and that involves a Skill Shot in a Sticky Situation), has no Escape Mechanism. Flash fixes that.

Time for the fighting, but what do we do first? Run for a lane? Go mid? Die?

NO!

Follow this guide, breathe slowly, and mastery of Cassiopeia will be yours.

Poison?

Poison.

Poison?

Poison.

Go for Noxious Blast, then Twin Fang, followed by Noxious Blast and Miasma. Then, go for another Noxious Blast and Petrifying Gaze. Then go for what you see fit. I usually go in the "pattern" seen above.

Ah, items. Items, items, items. I love me some items. Especially on Cassiopeia.

Follow the order at the top. Sorcerer's Boots, Doran's Ring (two), Rod of Ages, and Rabadon's Deathcap (two).

Sorcerer's Boots increase Movement Speed and Magic Penetration.

Doran's Ring help with early game Mana and Health.

Rod of Ages is best grabbed early, as to utilize it's "upon leveling" bonus.

Rabadon's Deathcap is god. Enough said. The Ability Power is Insane!

Battle Plans, Strategy, Tactic, Teamwork, etc.

Plans to utilize while alone. I believe that Cassiopeia is best used solo, but that's just my opinion.

Fololow IV.I.II. Jungle, Gank, IV.I.III. Jungle, Monsters and IV.I.IV. Laning to successfully mix and master all three of Cassiopeia's most viable builds.

Cassiopeia is unstoppable as a ganking machine.

Noxious Blast and/or Miasma to set up Poison and gain the Movement Boost, then Ignite and/or Twin Fang to add more Damage Over Time and deal desirable Burst Damage. If you can, Gank multiple Champions with Petrifying Gaze, then repeat from the top.

Cassiopeia also pack a mean punch against Monsters.

Follow the Ganking Strategies, but on Monsters. Around Level 16 or so, you can solo the Dragon (funny, so rare for a Caster to go for the Jungle, especially Dragon, but both of mine specialize in it)

Laning is also a piece of cake with Cassiopeia.

Noxious Blast and Miasma have nice Areas of Effect for Minion fodder, while Minion Cover and Turrets defend you very well from other Champions.

Strategies to be used when other players are around.

Cassiopeia is unique in the fact that she is the only Champion who can utilize the Abilities of other Champion. Specifically, Poison.

Singed's Poison Trail allows Cassiopeia's Twin Fangs to use their Cooldown Bonus.

Geometric Hell is basically large pools of Noxious Blast, Miasma, Poison Trail, and Mega Adhesive.

Teemo is one of the four Champions with Poison.

If you take advantage of his stealth ( Camouflage) and Poison ( Toxic Shot and Noxious Trap) with Cassiopeia's Noxious Blast and Miasma to set up a Jungle (or bush) of Poison. Bonus points for an offscreen kill :D

Oh Gods...

Twitch can be utilized with his stealth with Ambush and Ranged, Quick to Spread Poisons with Deadly Venom, Ambush, and Spray and Pray.

Cassiopeia can be utilized with her Ranged Poisons and Area of Effect Poisons with Noxious Blast and Miasma, along with her Stun with Petrifying Gaze.

Mix the Area Damage and the Pinpointed Damage, and you have a splash of Poisony epicness.

I have tried this multiple times and succeeded well, as well as with Teemo.

Now, I won't write it because it's rare and just a mix, but with Cassiopeia, Teemo, AND Twitch, the team is just Over Powered. Now imagine that, with Singed.

Poisongasm.

That just happened.

In conclusion, Cassiopeia is an extremely viable Champion, and one of (if not THE) most powerful Damage Over Time Champion.

Cassiopeia is amazingly used in the Jungle, Lanes, or on teams with anyone, especially Singed, Teemo, and/or Twitch

Thank you for reading thus far, and have a good time playing!