Skill Capping Abilities

I have noticed as I am sure many of you have that with demigods like Regulus when you complete the leveling of many of his skills it ends with a special ability as the last level (The stun that he gets instead of the last snipe and the 500 damage from the last angelic fury).  I really enjoy this mechanic as it rewards you extra for focusing on a certain spell all the way but also in the case of Erebus it makes you get Poisined Blood in order to get his vamp aura.  Normally poisined blood would seem like a waste of skill points as he has many stronger skills but provides interesting build options if you want to get the blood just to go vamp aura.  I am not sure if all heroes will have these cap abilities but I think it makes regulus a lot more interesting.  I am not particularely concerned with Rook or the Unclean Beast having them inparticular since they aren't completely focused on spells but for the Torchbearer (TB)  to have not of these cap skills is disappointing.  TB seems like the perfect candidate for a cap on one of his auras or something.  These cap skills would make TB more complex by making the choice of whether to go many spells or just a couple more complex.  Post your thoughts on cap skills and ideas about what I said with TB and if you think they should be added to other heroes.