Elemental Body II

School: Transmutation (polymorph), Level: wizard 5
Casting time: 1 standard action
Components: V, S, M (the element you plan to assume)
Range: personal, Targets: you; Duration: 1 min/level

Water elemental II: You gain a +4 size bonus to your Constitution and a +5 natural armor bonus. You also gain swim 60 feet, darkvision 60 feet, the ability to create a vortex, and the ability to breathe water.

After becoming a water elemental, the blood golem's attacks could not harm Nalu anymore.