Thus Spake Zaranephilpal/WhatInfernalsCantDo
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Now, as to what Infernals can't do: 1) Be perfect in an endeavor, rather than a specific approach to that endeavor. 2) Develop without invariably limiting and defining their bodies, minds and souls. You can't cherry pick your way out of this. 3) Develop extreme competence in one theme without losing some competence in opposing themes. 4) Suck.
I may be biased on #4, but you can probably trust the first three.
Source: [1]
