I didn’t check much the volatility but I do play the same game as yours which is Colosseum Clash that gives me the biggest losses.
I tried Horus which is my best slot game on the previous tournament but the result is the same. I’m looking the game which is the logo is Trump with tattoo but it’s not available on the eligible games for One touch.
I have no idea what’s best game on this provider anymore. LOL
Gifts of Horus is also a highly volatile game. I played it in the past but didn't have luck with it like you did have in the previous tournament

As for the game volatility, you can check it out right below the game. There is apart where game stats are indicated.