PROS
+ Lissandra is an insane champ for team fights all game along.
+ One of the best engage in the whole game.
+ Big damages mid/late if fed

CONS
- If you get behind it can get very hard to win
- Liss is team fight related so if your team is bad you wont hard carry

FIRST STRIKE:
Going for First Strike give you a lot of engage damages all game along, dont hesitate to poke with your Q every times you can prock First Strike on lane. It is such a great combo with luden.

PERFECT TIMING:
Since Zhonya is now so expensive, and still mandatory on Liss, perfectg timing give you a 750 gold power spike whenever you get your hourglass.

MINION DEMATERIALIZER:
Liss is verty good for ganking other lanes, so instead of leaving your lane unpushed, dematerializer give you an insage lane push to roam freely ( I usually use one on melee minion, and two on cannon minion)

COSMIC INSIGHT:
This rune is insane on this build it gives you item CD so you have Zhonya and Luden, your Zhonya and Luden CD will be more than reduced with this. And you will have your flash and ignite more often for good engages.

MANAFLOW BAND:
Since LISS need some mana early game Manaflow gives you the small mana boost you need.

GATHERING STORM:
Gathering storm assure you to have huge damages on late game, i think Liss is a good scaling champ.

LUDEN:
It gives you big burst which is a nice combo with first strike, magic pen is also very good on liss.

ZHONYA:
Zhonya give you so much tempo after engaging in fights, its a mandatory item on liss

VOID STAFF:
Magic pen is a good choice on liss

MORELLONOMICON:
Since Liss has huge AOE, you can prock anti heal on a big amont of enemies with your W and R, it makes Liss one of the best champ to buy Morello.

RABADON:
Rabadon give you this big late game power spike she need.

EARLY:
LVL 1 try to poke with your First Strike and last hit first minions with one Q
LVL 2 you can cancel any engage try with your W
LVL 3 you can try to bust with a full COMBO (E in> W > Q) but dont go too deep since after using E you have no escape

MID GAME:
Try to roam, follow your jungler, you can also gank lanes very easily. Dont hesitate to buy pink wards.

LATE GAME:
Its your time to shine, you can hard carry team fights. Dont go too early and when you engage dont hesitate to R their carry, use your Zhonya after full combo and let your passive and stuns do the rest.