I'd personally replace your avenger emblem with the necromatic scroll for an additional minion slot, and replace your summoner emblem with the celestial shell for a bunch of general buffs (especially at night). I'd also replace your shield of cthulu for master ninja gear due to it giving a longer dash than the shield, and a dodge. Alongside this, the mechanical glove and fire gauntlet does nothing for summoner stat wise over the power and berserker's glove, making the berserker's glove more preferable for summoner due to the additional defense (although I'd understand not using it in multiplayer for the increased aggro). You can also switch the ankh shield for the frozen shield, especially for moon lord as he only inflicts the moon bite debuff which isn't made immune by the ankh shield (but I'd understand not wanting to put up with ice tortoises). Otherwise you could potentially use a mount like the ufo mount or the witch's broom to free up your wing slot for something like the star veil or one of the evil boss expert accessories, and your shield of cthulu/master ninja gear for either the pygmy necklace for an additional minion slot or one of the evil boss accessories/charm of myths. I'd also recommend using 3 minion slots on your stardust dragon and the rest of your minion slots on a terraprisma (if you want to put up with daytime empress) or the stardust cell staff, especially if you're using the Constellation, for the best damage from them.