User blog comment:Leyrann/Why Chalice of Harmony is OP/@comment-5418658-20120827121401/@comment-4834593-20120827140649

If a champion that harrases whenever his skills are not on cooldown gets mana problems without making a kill already, Chalice of Harmony is worth it, because it near eliminates any possible mana problems, and still enables that kill.

To reply: No, sorry, Archangels Staff is just a bad item on top laners. And Manamune too. This leaves either a Tear of the Goddess, that doesn't make you immune to mana problems and does not give defense, or a Chalice that might give defense to your enemy laner, but for sure against jungler and/or mid laner, and also against support (most supports have more magical than physical damage), and elimatines mana problems.