This is the only example of a psyker that is not feeble I can find, and it is fan-made.

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There is also a reason psykers do not carry chainswords, lasguns/autoguns, and the like. They are usually too weak to do so. Even Squats, my lovely Space Dwarfs, have their Psykers get much less muscular and buff as they become Living Ancestors, although admittedly this is due to them being old AF.