Fishman discussed how to play Bane

I have 1,500 games under my belt as Bane, and here are my thoughts on how to use this hero as effectively as possible.
Let’s start with laning, since laning is the most important part of Dota 2.
Level 1: Buy Brain Sap and trade with the enemy level 4. Bane outdamages every hero in 1v1 situations at Level 1. IT’S IMPORTANT to buy a Flask with your first gold so that after trading blows, you can immediately restore your full HP and start disrupting the enemy offlaner as well.
Level 2) Level 2 won’t give you much, since Nightmare costs a lot of mana; you should only use this power spike in rare cases if you feel you can kill an enemy. Remember that mana isn’t infinite, and Brain Sap is more
effective to use. Level 3) Level Brain Sap to 2—this is your peak power during the laning phase; now it’s even harder for opponents to trade with you.

Laning phase is over, and now your main goal is to reach level 6 as quickly as possible. In most situations, it’s also very important to come and secure the active rune for your mid laner (starting around the 4–6-minute mark).

In my opinion, there are only one and a half viable builds for Bane in Dota.
My build always goes through Aether Lens, Aghanim’s Scepter, and then Blink Dagger.

Remember that night is your friend—it’s the time when you can play aggressively, since you can see twice as much of the map as other heroes. During the day, as a rule, you should stay where your team is.
Keep in mind that in 5v5 team fights, the enemies must kill you first to have a chance of winning the fight. You do a lot, and your life is very important, so after 20–25 minutes, if you and your team are running through smoke, you should be at the back, not the front. ...>

I NEVER level up Enfeeble to level 8, because it’s very important to have Nightmare at levels 4 and 7. Overall, this spell only becomes useful in the mid-to-late game

I believe Bane is good against all heroes in Dota, but if you see Beastmaster, Lycan, or Silencer, it’s better to pick a different hero. As you’ve already realized, Bane struggles against heroes with minions, which means Enchantress, Invoker, and Enigma are also very troublesome. You can’t set up against illusionists either, but Brain Sup works five times better against them—you can always bring them down to full HP with a single spell.