|Level||Cumulative cost ( Ancient Souls)||Effect (Dora increase)|
Sen-Akhan is a fairly important Outsider. While not as important as Borb or Chor'gorloth, it is able to boost your gold income by up to x100. Sen-Akhan boosts Dora, which doesn't scale very high or very quickly. However, Sen-Akhan's boost is the strongest of the Super-Outsiders, and Treasure Chest Chance does not decrease very quickly. For early-game and mid-game, you will want to keep Sen-Akhan at a fairly low level, because overspending does not give you more gold.
Eventually, past 24% TP, Sen-Akhan costs too much to maintain and is ignored for the rest of the game.
Each of the outsiders that buffs an ancient is holding one of the platonic solids.
Sen-Akhan is holding the dodecahedron, which represents the universe as a whole.