Love the whole idea and execution, concise and open for exploration by the players and the GM.
And, although I'd enjoy seeing some examples of all the extraplanar/interdimensional items that would fill his horde, I always thought the Rakshasa to be filled with adventure worthy potential, which is an aspect that is harnessed fully in the module.
The whole portal mechanism and the maps on the last page are awesomely done, genius idea.
Very good work!