The best pools are EARTH/ICE/MACE. Each have defensive toggles for smash and lethal with some cold or energy depending on the pool. If you want your controller to be the prettiest I suggest MACE as you can customize the shield effect to different colors and it provides smashing lethal and energy defense which are all very common. I feel plant doesn't need another aoe as our roots does x2 dmg from other controller sets and you should be getting your aoe dmg from procs. Proced out carrion creepers are a beast and so are proced out lightnight storm. But if I could minimize or hide the ugly ice armor I would choose ICE in a heart beat. Ice storm does ALOT of dmg and with enough recharge it's up every OTHER pull.