How To Predict Double Spells?

predicting a spell is easy, the mob starts blinking, but what about double spells?
if you dont know what i mean an example of a mob wich often casts double spells: doctor legendary
especially his second form, he often does a charge/teleport and a multi hit immideatly after, but i coudlnt see any difference to normal spell casts, so are these predicable and if they are , could you tell me how to predict these?

merci for reading and merci for every1 who tries to help

EDIT: i just saw death metal casting 3 multihits in like 5 secs, the blink was normal

 

I guess if you know it's one that does spell combos, assume that it will be a double spell and take action accordingly.

 

sometimes double, sometimes solo
well i just wanted to know if theres any way to predict doubles, but i think there isnt

 

I guess you just have to guess a pattern. For example:

Let's say the boss (x) does a spell combo of charge/teleport (y) followed by a multihit (z)

If x casts y, it will always follow with a z
If x casts y, it will not always follow with a z

You'll have to figure out which of those two statements is true. If statement 1 is true, then you'll be able to predict that you have to get the hell out of dodge. If statement 2 is true, then I guess you'll still also always try getting the hell out of dodge, except that now there's a chance that x will not cast z.

Let's be real I'm making this too complicated and I know jack about mob ai. This is just a shot in the dark.

 

Treat every spell that every enemy ever casts ever as death and get the hell out of dodge.
That's what I do if I don't know what they're casting.

Hell, it could be vanish, but you aren't gonna see me within 40 blocks of it.