Question: I'm a sniper rifle whatever that class is. who I a debuffer and who is a healer/debuffer? i want to try this combo as I'm starting to have trouble with same level fights (chapter 6)
You're ranged attacker. You'll doing almost all your damage supporting through a sniper rifle with TP Arts like Afterburner and only really using your javelin for buffs and TP gain. Equipment that raises your TP and helps TP gain is essential.
It doesn't really matter later in the game when you can equip a knife onto your sniper rifle for a healing sniper build.
The thing is that the sniper class takes a while until it gets decent damage. It really starts off slow.
Healers are characters like Irina, Celica, Hope, etc. They are knife skills under the psycorruptor class. These characters have much lower HP due to their healing arts.
Which fight is chapter 6? I can try helping you understand art combos and set ups.