I don't rate Diana; if that's the best Light option for you, then don't bother with Light. Songstress of Flowers Ramiel is excellent, works very well with Hathor (SR), who you also unfortunately don't have, but maybe some day. She's likely the last SR I'll remove from my wind team when I get SSRs to replace. Venus is pretty solid, she's a team filler for high damage builds (elemental) with good defense, so a strong option.