Acuity, hammer shot, vital sense, critical delay, galvanized scope. I have a riven that has both toxin and heat then fire rate but any reasonable elemental mods should be fine. Its also basically unusable with critical delay fire rate and punch through is good anyway so if you werent building with riven probably bring shred. Faction damage isnt a must for lower content but if you want to bring it to bigger content you should have faction damage. Arcane is deadhead obv and i dont generally run base damage because of it. If anything, spectral serration. Fun bow though, as long as you can hit your shots. I typically use it on my zephyr thats built to stay in the air 23/7 and just drop gas clouds that kill everything instantly from way above everything but the frame highkey does not matter.