Well, using my limited knowledge, "cleaving" means to chop, break in half, split, etc. Twain means twice. So, perhaps it's like "you've broke my heart in half", something along those lines? hopefully this helps you.
I would say the Tai-me symbolized the collective strength of the Kiowa indigenous people in the US and was used in their ceremonial dances and was a doll about 2 feet tall with feathers and mocassins so its theft would be an affront to their beliefs.
Throughout the Inferno ,Dante's states of mind changes drastically from when he first enters hell up to canto V.
As he experience More and More torture and suffering throughout hell,his perspective and attitude is transformed.
