why is my power steering fluid is leaking fast and i got blue smoke coming out

The LS400 with higher mileage can suffer valve guide seal wear and I have seen the power steering pumps and power steering high pressure hoses fail on these cars. Check the steering rack bots are in tack and that it is not the rack that is leaking. There is a service bulletin about the filter in the reservoir getting blocked due to internal hose deterioration of the high pressure hoses.

Check the vacuum hose that is atached to the bottom of your power steering reservoir, it might be sucking fluid into your engine...

Mostly the vacuum valve attached to the pump to boost steering when extra effort is required. diaphragm can leak and ps fluid will get sucked into intake manifold making engine smoke like an engine problem, of course blue smoke usually means valve or ring problems in engine.