All I can say for now is Double Awoken Ra! It is much more reliable than double Anubis for a reliable X100 team. Pictures below.
The idea of just about every floor is to clear hearts where you can (if they won’t attack you or you know it won’t kill you) and you will have a higher chance of matching 5 colors. For Zeus I had Indra from the previous 2 rounds (got a little close to losing on Athena and had to use him) which allowed me to have 2 turns, plus Kushinadahime if needed. This meant I had 3 turns to beat him. With X100, no problem. I used Zaerog for X2 for Dragons (X200 for Zaerog and Indra only) and this triggered the X4 for the Ra combination.
One turn and done
Now I gotta deal with this?? The hell! I checked and last 2 levels are Sonia Gran and Ultimate Zaerog with 9 million HP each. We’ll see!