I'm no good with translating Chinese literature (especially the nuances of it), and the handwriting doesn't help, either. If somebody else could try to translate this, that'd be very nice.
Here's what I have for the right:
天地八百萬神意 唯一柱恩慮兼備 永夜儚月琳枝華 千幻想猶輝箭詩
[Under the] ephemeral moon of the eternal night, jeweled branches blossom[Among the] wills of 8 million spirits within heaven and earthMs. Eirin of EienteiThe sole pillar of kindness is to have bothA thousand fantasies still shine like arrowed poems