Complex sentence: He forces Manji back against a tree which is covered in a netting of rusty hooks, which sink into Manji's back and hold him there while Hage turns his attention to Rin.
Split into simpler sentences: He forces Manji back against a tree which is covered in netting of rusty hooks. The hooks sink into Manji's back and hold him there while Hage turns his attention to Rin.