Not sure if this is well known, but during Arthur’s powerup cinematic (and a few other characters, as well), you can input any special move and it will automatically come out after the two frames of recovery. You can also input a super and if it is not a valid DHC, Arthur will buffer that super; e.g. with Arthur + Taskmaster, you can do armor powerup and buffer LV3 during the armor cinematic, and since Task has no DP input super, you will immediately go into Fire Dragon (again, with 2 frames of vulnerability in between).
In addition to specials/supers, you can also buffer S or back+H. For some unknown reason, toward+H does not work. You also cannot buffer armor powerup into itself (if you are going from naked to gold); you’ll just get a QCB toss as you exit the powerup.
Now, here’s the shenanigan part:
During the armor powerup cinematic, if you buffer a special move, you will get the version of that move that corresponds to Arthur’s armor state at the time you buffer the move. For example, if you do powerup and input QCF+H as fast as possible, Arthur will shoot a silver crossbow as soon as he finishes the powerup animation (even though you have gold armor on). However, if you wait until slightly later in the powerup cinematic and then input QCF+H, Arthur will immediately shoot a gold crossbow after the powerup animation.
This isn’t just trivia. The fact that you can buffer Arthur’s invincible DP+M during the powerup animation is quite useful, and (with gold armor) you can XFC that into DP+M loop for the kill. However, if you buffer DP+M too early in the cinematic, you’ll get the silver version (which does not cause spinning knockdown), and your opponent can flip out before you can XFC and continue the loop.