One of the strongest disables in the game. You can use it to setup kills with your team early on, but later into the game it may be better to either initiate with it or hold it off since you're most likely to play as a tanky frontlaner which increases your chances of being interrupted mid-ult

You can use it to both harass opponents early on and setup kills. It can also be used for it's 1sec invulnerability after cast which can save you or your allies (or your enemies) from a projectile or a spell (like X-Mark)

You don't really need it yourself, but it's usually a strong team oriented item. You may consider dropping Solar Crest in favor of Spirit Vessel

Another mana solution, may replace Bracer, but it's more expensive as well

Additional movement speed and armor are pretty much all Bane needs seems he doesn't need attack speed and stats more than he already has

Good for cases when you won your lane early on, but can't finish the game early. Bane struggles with farming after laning stage, so it may be a helpful pickup

Reliable disable and mana sustain

Good thing to have against slows and similar stuff in its nature (X-Mark)

Against strong single target disables (e.g. Doom)

For a hybrid core way when you need armor

Natural upgrade to Medallion and useful buff for your team

Strong regen aura and useful item to have in general. Good pickup if you're playing more of an utility core and there's no better Greaves carrier on your team

Against high attack damage cores

Against magic heavy lineups

Against silences and purgable slows

Good item to save allies (or yourself) from being focused