Our playing styles are almost exactly opposite. I prefer battles to be easy, ideally OHKs, even bosses (unless they have something good to steal!). I like to explore, find the treasures, complete lists, and enjoy the story.
Obviously, my play style is OP. That being said, I like the STR+32 jewels and the Variant jewel* (it takes a lot of room but can seriously up the damage done). If you’re a magic user (meh, magic is too slow. lol), You might want some INT+32 jewels and an MP Add jewel (adds 1000 mp to character at start of battle). Oh, yeah, almost forgot the Impatient jewel that shortens the magic/skill wait time.
If you’re using Auto-battle on the mobs, a Next jewel is awesome. If a character OHK a monster, they’ll automatically move on to the next monster, and keep going until they miss or don’t kill it in one hit. Speed is always a good attribute. I have Hi-Speed Jewels on at least 3 of my characters.
*(Damage increases by 1x for each enemy on the screen at the start of battle. (One per character.))
NOTE: For other readers and lurkers…here’s a link to the Jewel Synthesis Guide .
Be silly. Be honest. Be kind.