Editing Warhammer 40,000/Tactics/Necrons(8E) (section)

===Choosing Powers===
You cannot choose several of the same power unless you've taken every other power already. Bringing two Tesseract Vaults and a single other C'tan allows you to take two of the powers you don't want your Tesseract Vaults to have and have two Tesseract Vaults with identical powers. Or if you have two C'tan and a Tesseract Vault you can take the same powers on the two C'tan.

Antimatter Meteor and Sky of Falling Stars are usually great on C'tan, while Seismic Assault will usually be bad. Cosmic Fire is usually great on Tesseract Vaults while Sky of Falling Stars and Transdimensional Thunderbolt are usually bad, note that Seismic Assault is still the best option in some games on C'tan, but those cases are going to be rarer than on a Tesseract Vault. Some powers are very circumstantial, having a good backup power is a good idea if you choose to take one of them instead of taking two circumstantial powers, like Sky of Falling Stars and Seismic Assault for example.

One thing to note is that for Transcendent C'tan Shards you want to generate your random personality trait(s) before assigning Powers of the C'tan so you don't give them a long-ranged power only to find out that you've got re-roll failed wound rolls in close combat.