Re: What Triangle Jewel do you use in Level 9&10 decks?
Congratulations on getting deck 9! That's a huge accomplishment!
Although Power Pips doesn't benefit a TON, that's still the best way to go in my opinion. On middle/upper stages you are less likely to get stuck at 7 or 8 pips if you're trying to use a 9-pip hit and at lower stages you can get a power pip when it was otherwise impossible!
The only other viable alternative is accuracy. If you tend to use opposite school spells, then you only need 5% typically, but with spells like Articzilla, you could benefit from having 10 or 15% extra accuracy to not have to deal with the fear of fizzling. Also! If you're one of those players who likes to use storm spells for every deckathalon, then go with some storm accuracy!
Otherwise the only other options are shadow pip chance and item cards, which are both useless in deckathalon.