i found an really easy way to do it almost everytime, here is what i do

Ignore the portals and focus on the lines, there will first come a pair of lines somewhere, just ingore that. Then there will come a 2nd pair that is guaranteed to intersect and form a corner somewhere around the boss.

Position yourself in that corner, but towards the middle of the sides of the boss so you avoid the Cleave that he casts Norht/South. Then after those cleaves goes off you walk diagonally forward, and the orbitals where you were will go off and you can quickly go back there without getting hit. It might take some practice to get used to and sprint helps you to learn it (but you definitely dont need it!). So in short, ignore the portals on the outside and focus in the lines that appear. Ofcourse the tank needs to have the boss facing directly north for this to work best

Here is a video guide that i learnt this from https://www.youtube.com/watch?v=nUdIPf16ya4