Magemeta is where I'm completely dying, although I'm also lacking good physical bursts.
Then again, that 30% null damage thing seems like the next upgrade to Wall and I'm worried that you'll need that to beat the high end content later on.
The 30% thing is more of an upgrade to healing mechanics than mitigation ones. It isn't meant to supplant wall effects.
Despite the presence of Alph's burst this actually isn't a great mage banner. Papalymo's SSB is really the only other mage relic on it.
If you want to swing hard for mage relics I would recommend waiting and trying a pull on the Summoner Nightmare banner coming up.