Let's start off with the basics.
To have a movejoint that moves effectively, you want to have this event:
As you can see, Extra parameters are shown. Extra parameter 1 should be either 5 or 7, depending on how efficiently you want to manipulate the movejoint. If you're extremely lazy you can just set it to 1, but you'll only be able to manipulate extra parameter 2. You don't want that.
Extra parameter 2 would affect the distance the move joint travels.
Extra parameter 3 affects HOW the move joint travels.
Aaaand Extra parameter 4 affects the time taken for the move joint to move from point A to point B in frames.
Now that you know what the extra parameters do, you want to set the move joints on a X and Y axis.
As shown in the picture:
Two move joints are shown, one is the parent part, one is a child part. you can have more of these, of course. But for demonstration purposes, I'll just go ahead with two.
As you can see, one of the move joints will travel horizontal, and one vertical.
To manipulate them individually, an event such as:
MAKE SURE YOU TICK THAT BOX THAT TELLS YOU NOT TO DELETE THAT EVENT. You'll probably use it again anyways.
You can control the move joints' position using variables. Using a trigger to change the variables, you can use this to change both the move joints' position at the same time. It's very handy.
To move to different positions, just use a different value for the integer and don't repeat it.
You can also change the timing of the movejoint, by manipulating extra parameter 4. just try to keep it at a low frame as a condition.
For the boss to 'swing' on the same variable, I suggest that the move action be set to 5, or 6. In case that the boss has multiple forms, and needs to return to it's original position, a trigger with variable 0 can be used, signalling the move joint to move back to it's original position of 0.
I hope this has been a helpful guide. Brought to you by [strike]Aperture Science[/strike] me
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Okay, the more in depth stuff comes next.
We want to have the best movement possible for a fixed area boss, right? Well you don't just want it to move around in a static fashion. This can be corrected by the 'Harf-fixing' connection type (My favourite).
The number to the side is the frame count; that is to say, the number of frames it would take to return to the position it would be in - if the connection type was 'fixed'
So now we have another connection type on our hands,
Remember the move joints I told you about, in the last segment? Wondered how the boss hovers above the player? Yeah, you can change the connection settings of that too. Simply have a trigger, some additional horizontal move joints, and set the connection type to Player Axis.
Like Harf-fixing, the Player Axis connection type also has a frame counter. (the number of frames it would take to return to the position it would be in - if the connection type was 'fixed') Simple, yes? You can set a trigger for this, and a trigger to revert it back to it's original connection type.
Now, the deciding factor for your boss' movement would be The Extra Parameter 3 of the move joint.
It can range from a -1 to 11. While I will explain the essential values, the rest will be better to experiment with yourself.
Value 1: Static Movement. Speaks for itself, however, it is quite handy for that 'teleporting' effect when combined with an extra parameter 4 of 2.
Value 3: Rather Smooth Movement. Once again, speaks for itself. It will move with a 'wave' starting slow, speeding up and slowing down. All in the specified frame. This can be replicated with the Harf-fixing connection type, though.
and Finally, Value 7: Continuous movement.I prefer the 'teleportation' effect over this one, as it is quite difficult to master, but if done correctly, enables continuous motion of a part in a single direction, until the extra parameter 2 is changed.
I guess that just about covers the section for basic move joint use.
Brought to you by [strike]Egoraptor[/strike] me