Smelly Cerberus Breath

Either if you need antiheal or situational items depending on your match. Maybe you are against a lot of carries Nemean could be a good idea instead of Pridwen. Spectral if it's really necessary and your support can't think by themselves to get one. Totem of Death could be worth with the new changes, but you won't tank as good. Most of the time Magi's will be very needed so they can't stop your smelly breath, but if they can't really stop you, Discord will be a good replacement, plus, it has CR. Too many freaking slows? Hussar's always a good option to not get tilted by 50 slows. I usually stick to the main build, but if you really want to, these are the options.

If you get your stacks high enough to at least 50, would be fire if you can fire all those extra ticks again with Myrddin. More slow perhaps? Isolation. Helm of Darkness can be a fun replacement to Hextone. And, remember to ward, please, don't get ganked, gank the gank. (Free Stacks)

Explanation and Tips

Early game you want cooldown, as much as you can. Both Sands of Time and Chronos will get you the cooldown you need to get your stacks going, but be mindfull that you are squishy, but also gives you kill potential. Use your ult almost on cooldown to get some free stacks. Shield of the Phoenyx replaces the healing you lost with the aspect and heals per every person you breath at, or ult, that a lot of heals. With Ancile you can silence the whole enemy team, activate it and your 2 will Silence anyone that you hit at any point of the ability. Pridwen gives you a little more survivability, CR and a slow that stacks with the slow from your 2. Magi's is, most of the time, indispensable. Hextone is a really good item to engage, disengage, or chase a kill. Good Luck, and Have Fun.