So you still haven't figure it out kid? huh..
"Marty was never subtle but then again, that is what he liked about Marty. He may not be sharp but he sure is reliable and knows where all the bodies are buried."
The Pantheon just isn't a fancy house to show off your wealth. But rather a morgue for all your lost soldiers.
Thats right the ghost stories are all true. Those noises your hear at night aren't just the place expanding and contracting. It's roaring with life. Well, not exactly the living kind. But those who used to be. They're waiting to be called upon, to return to your ranks and get their revenge. They wont rest. They can't rest, until they get that bastard back!
The Pantheon will be a building that will keep a limited number of the soldiers you lost from being attacked in a "reserve". Where you will be able to purchase them back at a slight discount. After the Limited capacity is exceeded all excess soldiers will be lost permanently. Leveling up the pantheon allows for more soldiers to be saved from being lost in defensive battles.
The advantage from this is you'll be able to rebuild you army rather quickly and be able to get revenge.
It will improve the quality of the game for players who are constantly harassed.
The risk will therefore be in attacking other players. Defensive battles will not penalize players as much as offensive attacks will.