Well, actually, that,s what I want to create... But can any of you tell me the page where it is written if an NPC created as a PC would is wheter a standard, elite or solo? I just can't find this info...
It's not stated because you're
NOT SUPPOSED TO BUILD NPCs LIKE PCs
Once you have understood fully the risks of not following these instructions, you're free to do about anything, but don't come around asking for people's opinion on any related matter, because they will blatantly say that you were foolish to start with.
That being said, Every of my non monster elite NPCs are built with PC rules, and so they have almost complete sheets. This takes ages to build, but I'm a passionate^^. This suits my very personnal game, because it's far from the typical quest based game with dungeons and stuff. It's more of an NPC centered quest than an heroic adventure, but my players love to feel competitive with other same leveled non PCs. Anyways I don't award experience in the recommended manner and so I cannot guide you for any XP related stuff. Just so you know, implanting such NPCs into your game will bring up multiple problems as previously stated:Loot, difficulty, balance and necessary expanded ressources(items, encounter and dailies, consumables)
So you could do this, which requires an iron grip into your game, or just follow the rules in the books.
I dont think anything forbids you to create an NPC with the paladin class(DMG 188) then following the rules for creating elites or solo monsters(DMG 185) add one or two class templates to your "monster".
Following these rules, you could build a lvl 4 paladin
add him a class template of warlock making him an elite lvl 4 with 2 at wills, encounters and dailies.
Then if you really want to make him stronger, you could make him a solo, adding Paladin class template to your paladin/warlock elite making him a lvl 4 solo with tons of hp, 3 at wills, dailies and encounters(2 from paladin class 1 from warlock). This would make him some kind of paladin/warlock with paladin as his primary class(or whatever) and you could even calculate an exp value for him following the rules for a lvl 4 solo.
Now looking at this you figure out that this solo is much stronger than a regular PC, so I'm guessing either i missed out on some rule that states not to apply class templates to non monstrous NPC, or that the NPC design guideline is a little flawed in early levels.
Nothing forbids you to do anything, but just be very very careful when you step out of the boundaries...
EDIT: Also, if this is a nemesis, you might want him to come back, so kind of plan that he will get defeated and find a way for him to escape... Thats if he's not already strong enough to take on your whole PC team, which you might not want.