link strategy for multiple domain names with the same theme.

Hi there,

I am looking for a good stategy to link my domains. Let me explain the situation.

I have about 25 domainnames relating to games on one server, I have another 25 domain names on another server.
All these domain names are for example  game-name1.com, game-name2 each site is about one game.

Then I have 2 sites that are more like portal sites, they contain an overview of all games, the links on the main page link
to a specific game page on that same domain.

Most domain names have a good position on there main keyword (that is mostly the same as the domain name)
However not one page has a (visible) pagerank.

I wonder what's the best way to link these domains to each other.
Attached you'll see a workflow.