Hume

Hume is Mia's half-brother. He is half-breed, half Dungaga and half human as a result of being born by Thelia and Gar. There is tension between Hume and Mia in the beginning and he later betrays Mia, but in the end Hume joins with some Dungaga rebels to help Mia, and he redeems himself by taking an arrow to the chest for Mia.

Strategy
Hume is easily one of the hardest bosses in the game. To defeat him, let him jump over you, and run under him so that he's on the left and you are on the right. If the bubbles are not hurting you, ignore them. As long as you attack him repeatedly, the bubbles will not hurt you. Attack him repeatedly until the bubbles become overwhelming (and attack from the top).

Then, walk more to the right, and he will jump and follow. When he lands, he will use his drill. When the drill retracts, attack him repeatedly until the bubbles overwhelm you again. Repeat.

When you become cornered, pop all the bubbles with your Dagger weapon. It is very hard to jump and use it, so if you have problems doing this, practice. When you pop all the bubbles, he will jump, then RUN under him. The strategy is the same, but mirrored: After he jumps, Hume will drill. Attack him when he retracts. When the bubbles become overwhelming, move left and he will jump and follow. Repeat this. When you get cornered on the left (hopefully you won't!), pop all bubbles, and run under his jump.

Additionally, he follows a pattern: first, he will use bubble then drill then jump, afterwards he will always alternate between A: (bubble, bubble, drill, bubble, jump.) and B: (drill, bubble, drill, bubble, drill, jump.) Understanding this pattern allows to predict everything he will do and consequently to easily beat him, even without using daggers.