Revenge killer / Attempt to sweep
w/ Charge Beam
Azelf @ Expert Belt
/ Life Orb / Leftovers
32 HP / 8 Def / 252 SpA / 216 Spe
(*)
Timid - Levitate
<Psychic>
<Flamethrower>
<Grass Knot / HP Fighting>
<Charge Beam>
(*) When you decide to use HP Fighting, put 4 Def-EVs into Spe
Azelf is rarely seen outside the lead postition, but with it's fantastic special move pool, speed and special attack Azelf is also a great special threat and can sweep with Nasty Plot and Calm Mind. But Azelf has also it's disadvantages - it's frail and weak to Pursuit and Blissey and Snorlax are still common.
This set attempts to revenge kill (and luring) in midgame play, while still being able to sweep late after your counters are gone, considering you are still alive until late game. This is accomplished by Charge Beam, but I'll explain it later.
Maybe you noticed, but the moves are the same as the one in Smogon's NP-set, beside Charge Beam replacing Nasty Plot. Psychic is for STAB, Flamethrower and Grass Knot / HP Fighting for coverage. Btw. you can run other moves for coverage, Azelf has access to Ice Beam, Shadow Ball and other HP (like Ground) as example, if you want to get walled by other Pokémon (maybe you noticed, but Latias resists all moves in this set). Charge Beam is the move that makes this different from other Azelf sets, but I'll explain it now
Charge Beam is the big difference in this moveset. It's a weak special electric move with 50 base power, which has a 70% chance to increase your special attack by one level, while it has a 10% chance to miss. So, Charge Beam has a 63% chance to increase your SpA, when you also considering the miss rate. While you usually see Charge Beam on tanks like Cresselia and Rotom-A along with Substitute, Charge Beam is used offensively on Azelf.
Don't imagine to set up on something with Charge Beam and then sweep. Imagine this situation:
You use Azelf to revenge kill a MixMence, after it killed one of your Pokemon. It's at low health and SR is up, so when it switches out, it won't be able to switch in again, because it will be killed (SR). Instead of using Psychic to revenge kill Mence, you're using Charge Beam to kill Mence. Now, when you're lucky, your special attack has risen and you can attempt to sweep your enemy's team, when your counters are dead. These situations aren't rare, they happen very often, you can also use Charge Beam, when you're expecting a switch.
You can use many items for this set. Expert Belt is my favorite one option. This set has four special attack with a decent coverage and you can expect to see SE hits very often. Also it's fantastic to fake Scarf/Specs until late game and you can catch many Pokémon by surprise. LO is nice, because of the additional power, but don't expect to live long and it will really kill itself. Leftovers is for more durability.
The EVs are a little bit different. Timid Azelf with 216 Spe will outrun non-scarf'd Pokémon with 110 base speed, most notably Latias and Gengar. When you still want to speed tie with other Pokémon with 115 base speed, like Starmie, other Azelf, Ambipom and Raikou, and scarf'd Pokémon with 60 base speed like Magnezone, you can put the defensive EVs into speed. The defensive EVs are for some extra bulk, so Weavile's Pursuit won't KO you and I have the feeling that I can take Scizor's BP waaaay better.
To answer some questions, that will come up:
Nasty Plot / Calm Mind > Charge Beam! - In my opinion you need screen support for setting up NP/CM, because you won't find situations where you can set up. Walls will cripple you and even deal heavy damage to you and you rarely find something locked into EQ. This set also won't easily get CB, but you somehow can sneak to get some CB by revenge killing and force switches, by faking a Scarf/Specs. Also, this set is meant to revenge kill, while still being capable of sweeping in late game.
Thunderbolt > Charge Beam! - Charge Beam is not for coverage or dealing heavy damage. Thunderbolt is generally a bad move on Azelf. I don't think I need to explain this.
Blissey > You! - Yes, this is true, but look at the partners section below.
Alakazam > Azelf - No.
Now, I want to show you a very good partner: Tyranitar.
This set has actually no chance to beat Blissey and you need some CB boosts to get rid of Snorlax, which won't happen. Also, Latias resists all move in this set and with Latias' good SpDef it can easily tank Azelf. Azelf is weak to Pursuit and yeah, that's awful. Also, Azelf is frail and doesn't resist Priority. (CB)-Tyranitar can easily deal with Latias and weaken Blissey with Pursuit, so Azelf can beat it, when it switches again into Azelf. Though, you need a way to deal with priority.
Btw. sry for my bad grammar and this big wall of text. I tried this set and it really works well and I'm beggining to like it. NP Azelf was always a disappointment to me, because of how easy it's stopped, even after the main threats are gone. This set gives me the feeling that Azelf is more usefull even outside the lead position.
-0²
EDIT: Obviously SR is needed to give this set a lot of potenital, Spikes are also a fine choice to use.