Agreed with wacky xD
For 22 - 26/27, I went to Burning Hill (BH)
27 - 36, I went to Moonlight Tomb (MT)
And from then on I'm now visiting Vine Tomb (VT) @-@;
I'm an easy soloer, so I tend to solo yellow mobs.
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I didn't party a lot in my 2x's, so if you party you might want to try lvra's suggestions xD
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Personally, I would keep the bow, and if you want upgrade it though if you don't have a backup don't do it @-@; And +6 is already pretty good.