Presuming you mean "template" not in the game-rules sense, but rather in the generic sense of general guidelines to follow, ...there really aren't any. At least, none beyond having entities in your game that predate the current cosmos at all. Any such entity, and particularly any that induces madness in creatures that see it, would be an element of Lovecraftian horror regardless of alignment.
Though of course, the likelihood is that any LN-aligned being from such an era would not have a madness-inducing form, at least not if it was an Outsider. Since they represent beliefs on a physical level, Lawful Outsiders tend to have very set, regular forms that are easy to follow the outlines of and take in "at a glance" even if they don't remotely resemble anything from the Material Plane.
Actually I think Modrons could fit that definition quite well- they're not made from petitioners on Mechanus, are they? The vaguely-humanoid appearance of the top-tier modrons could be a pointer to them (or at least Primus) being one of the architects of the current humanoid form, rather than because they themselves originally came from spirits of humanoids.