What I had in mind was playing upon the old-world Tzimisce's traditional tendency to conduct their experiments in isolation to create a character who, having spent most of his existence in seclusion seeking the secrets of Metamorphosis, or, alternatively, having been inducted into his present state by such a sire, has recently been forced out of his haunts (possible causes include the encroaching of the modern world, or the implications of the slaying of Baba Yaga if he originates from Eastern Europe), and must find a place in Kindred society. Despite the majority of his Clan being affiliated with the Sabbat, he sees the latter's enforced ideals of action and communality as an obstacle to his studies, which he attempts to continue, and finds the status quo upheld by Camarilla as a more desirable environment for his work; and, as he has heretofore not had much contact with either of them, he is not subject to prior loyalties, causing his choice of allegiance to be founded on pragmatic reasoning alone.

It stands to reason that a Tzimisce would be widely distrusted and grudgingly tolerated in the best of cases, which is indeed the reason for him being unable to act directly in the Camarilla's power struggles - and power is a commodity he craves, if only since it would allow him greater freedom in making people disappear in disreputable quarters. In order to gain any sort of influence, he would have to rely on thralls and those bold enough to privately seek his services as a practitioner of Vicissitude (altering the appearance of ghouls for infiltration purposes comes to mind as a potential marketable use of the Discipline, distasteful though it may be) in return for vaguely defined "favours".

As mentioned, this is a mere idea, not especially elaborate beyond its basic concept. However, if such a character were acceptable at all, it could be further refined to fit an established setting.