Shojin is for 35 spell haste + 12% skill damage. It stacks super well with 6% damage bonus that liandry gives. The 12% Shojin passive basically gives as much damage for boxes as any other AP item would, but also provides with great amount of spell haste for better setups. The trade-off here is shiv damage is lower when the passive isn't stacked. But we also do gain more AA damage. Since Liandry's is the best damage item Shaco has, the great amount of spell haste Shojin provides allows us to build Liandry's while having loads of boxes to peel and set up objectives.