Reposting this explanation I wrote in a private conversation since others may find it useful.
Azwel is tricky because he has "modes" that are related to but not quite the same as his stances. In fact, the modes aren't really stances at all; the closest analogy would be Viola, whose moves were different depending on whether she was holding her orb or not.
Azwel enters a mode after using that mode's weapon. Take 2A for example. The first time he uses it, it will be i22, and there will be a little blue flash on his hand to indicate the mode change. After that, if you do 2A again, it'll be i14, and there won't be any flash, since he's already in Sword Mode. At this point, all of his Sword moves will come out without that extra delay from "creating the weapon" (which is the game's explanation for the mechanic).
Now, if he does a Spear or Ax attack while in Sword Mode, there'll be a new flash (red for the the axe, and I think a deeper shade of blue for the spear), and he'll switch to that weapon's mode, leaving Sword Mode. For example, he could do 6B, which would be i22 as he creates the ax for it; but if he does it again it'll be i14 (and any other Ax attack will be its normal speed). The same applies to using ax moves outside of ax mode or spear moves outside of spear mode.
He has a fourth mode, Almighty, which he enters after doing 6A+B, 8WR A+B, a throw, or the Almighty version of his A+B. In Almighty mode he creates all his weapons and can use any of them without the 8-frame delay. But if he does use a sword attack, for example, he switches to sword mode and loses the immediate access to his other two weapons that Almighty Mode gave him. Entering Soul Charge also puts him in Almighty Mode for its duration, regardless of which attacks he uses.
There are a few exceptions to the 8-frame rule, which are listed in the note on the wiki page. Namely, his jump attacks, back-turned attacks, and dual-button attacks are always the same speed regardless of whether he has the right weapon equipped or not. (You can see the flash on his jump attacks that indicates a mode change, but the move will have the same impact frames as usual.) All of his Almighty moves are dual-button inputs, and so are never subjected to the 8-frame delay. His few "kick" attacks (8A+B, e.g.) don't have any effect on which mode he's in.
Now, his stances are an alternative way of equipping a weapon that circumvents the 8-frame delay, but when he enters the stance, he's limited to the moves that are provided by it. If he does an attack from a stance or just waits for the stance to finish, he'll remain in the mode corresponding to that stance's weapon, but can use his regular attacks normally.
Finally, he has three "weapon arts," which are moves that can only be done when he has a weapon equipped. In spear, sword, or ax mode, these can be done with just B+K. In Almighty Mode, he has access to all three as 4B+K, B+K, and 6B+K, respectively. Using a weapon art causes him to throw away the weapon he was using, so he has to make a new one to be able to use them again. (If he lands all three weapon arts in a round, 8WR A+B becomes a Lethal Hit.)
His moves are listed in the wiki using the impact frames they have inside their respective modes. If the Notes column says "Sword," it means that that move will have those impact frames in sword mode, or else will be 8F slower and will put him in sword mode. If you see a move such as 6BA which says "Ax ~ Spear," this means that the first hit is an ax move but the last hit is a spear move; so the first hit alone will put him in ax mode, but the second hit puts him in spear mode.
The trick to playing Azwel effectively is to understand what his options are within each mode, the safest ways to transition between them without being interrupted due to the delay caused by creating a new weapon, and to proactively switch to the mode that best suites the pace of the fight: spear for defense (forcing the opponent to make "errors"), sword for speed and utility ("balance"), and ax for offense ("war").
