the thing about lissandra is, as most have mentioned, her range. Her Q is really short at its base range not counting the initial pass-through. Her W is also short range as is her ult. The only real long range skill she has is her E which has a high cooldown and is also one of the major aspects of liss as it serves as a zoning tool and an engage, escape, and re-positioning tool and almost an identity to her. She's a mage that you're going to want almost literally in the middle of the teamfight as her spells almost all (or rather, they all do if you count her E being a self-cc) crowd controlling abilities. A W that roots everything in a small radius of herself which is good anti-gank, especially if a poor bastard tries to dive under your turret. her ult can be a tricky decision whether to ult an enemy or yourself sometimes since the effect lasts longer (i think close to double the time) on yourself,but the drawback being that they need to be in it to take damage, whereas the enemy-cast version will stun/suppress(forget which) the enemy,guaranteeing the damage on at least that one person and you can also unload the rest of your spells on them in the mean time.
Due to her nature of needing to be IN the fight, building things that come with built in armor (zhonyas) or MR (athenes/abyssal) helps her out quite a bit, with zhonya's active synergyzing quite well with her self-cast ult as enemy team can wait for her self-cast ult to wear off to focus her, only to have a zhonyas after that to annoy them or wait for CD to E away or W root them just to increase survival chances.
I personally like liss, just E-ing in from jung is funny as hell.
