If you can check out the Enthoo Pro M RGB/Special edition better case then either the P400 or the Masterbox.

https://pcpartpicker.com/product/KnWrxr/phanteks-ph-es515ptg_swt-atx-mid-tower-case-ph-es515ptg_swt

But in between those models its a give and take the Masterbox you get three RGB fans.

Both are pretty bad for airflow unless you do something like vent in from the top or back.