Its blades are its  spears. 
( ( Its blades ) ( ( are ( its spears ) ) . ) )
(ROOT (S (NP (PRP$ Its) (NNS blades)) (VP (VBP are) (NP (PRP$ its) (NNS spears))) (. .)))
It uses real spears rather than a substitute.
( It ( ( uses ( ( ( real spears ) ( rather than ) ) ( a substitute ) ) ) . ) )
(ROOT (S (NP (PRP It)) (VP (VBZ uses) (NP (NP (JJ real) (NNS spears)) (CONJP (RB rather) (IN than)) (NP (DT a) (NN substitute)))) (. .)))