Jonathan Maccabee
Slightly above average height of an athletic build (though more fit than anything). Dark hair with a slight beard around his mouth. He dresses for the occasion of course, with normal wear being suitable pants and shirt one would expect of a noble. He keeps his personal shield on him at all times these days (can never be too careful) but only sometimes has a weapon on hand.

While he is polite and friendly, he also tends to speak with a 'matter-of-fact' quality that is more direct than not among those friends and loyal agents of the House. This is his 'being himself' mode of course, where he speaks his mind and voices his opinions without fear of offending. Part of this bluntness seems to be coming from the more logical and rigid training he has received in the past several years as he has been training on the path of a Mentat.  Of course, his social personality is quite different, becoming more nuanced, charming and even sly at times. A sort of second mode he puts himself in for dealing with outsiders, but still developed and natural to him to not be 'fake'.

Known Information: For the others in the House, of course, they would know of him being the Heir and some of them likely have helped train him over the years. Particularly the Warmaster, Spymaster and so forth. Keeping him updated on House matters so that - in the worst case situation - if his father was killed or died, Jonathan would be ready to assume command without too much necessary information needing to be conveyed. Beyond regular training to keep him familiar and skilled in all manner of methods and styles that the House excels in, most would know of his training in recent years along the path of a Mentat. If one of the others is already a full Mentat, its highly likely they have been handling his training as well.

Publicly, to those outside the House (and general 'common knowledge'), he'd be a bit of a minor mystery as the House is catapulted to the forefront. He's on the young side, but still a full adult in his early twenties. He's likely received all the normal training a noble son (and heir) would receive, so even as a new Major House he'd be expected to be familiar with most matters if not quite practiced given his age. Those Houses with more intrigue oriented activities may even have heard of his training and skills, though how extensive would depend also on how good their sources were.