Well, from what I can see, you set the sword angle to 45 degrees, spawn a bullet, then set bullet angle of motion to sword.angle - that's why it moves at 45 degrees.
.
A few other things - you are using the signals wrong. It makes no sense to send a signal on every tick.
And you don't need to "Pick last created" in event #40. The bullet instance gets automatically picked in event 39 when you spawn it.