Death Ward + Elemental Armour on the same item
"Oh, sure, no problem." Death Ward is cheap, about one upgrade each. Rings of elemental armour are about twice as expensive. Both together is doable for four upgrades each. They'll have to be made, but you can get them done in a few days.
canceling out one attack per round
"That sounds more like a skill thing. If you want to cancel damage, that's what potions are for. Blocking attacks or redirecting them are skill things, really." (The physical effects you got from the scabbard guy combined with Spar's duelist skills essentially prevents this. Except for big Trence's Cover ability.. which means attacks would just hit him.)
Sessha does add "Sonic Stun can do that. I don't expect Spar will fail the save very often at all."
Ask an armor guy for specifics on Resist All on armor.
It's easier to do on light armour than heavier, and easier to do if you sacrifice physical defense than not. And it's easier to do if you leave a weakness to be covered by an emblem.
You're out of gold or better emblems. Working it out for the four party members..
Trence needs basic resistance to everything. The cheapest solution is to buy a gold fire emblem and install it in some custom medium armour. Net cost is three upgrades (selling his existing armour) for six defense, zero magic defense, and single-resistance to everything.
Willis is cheaper, thanks to the Web Shooters, granting one rank of earth and fire resistance. He can wear the equivalent in protection for only two upgrades, with the emblem shifting over to a lightning one. 6 defense, zero magic defense. Single-resist everything but fire and earth.
Sessha is also cheaper. It'll only cost one upgrade for the trade, given her lighter armour, but at the base is a notable decrease in protection. One upgrade for five defense, zero magic resistance, and single-resist to everything. For her light armour it'll only need a silver water emblem, which you already own.
Alice can save money due to horse barding, but heavy armour is more expensive. Not having to cover for wind helps some. For her it'll be four upgrades for seven defense, zero magic resistance, and single-resistance to all but wind. It also turns out to need a gold Lightning emblem.
These are all equivalent to [+5] armour, but their defenses and magic defenses are fairly low and can be improved on with more money spent.
Is there a way to turn a party fight into a set of 1v1s? Hall of mirrors spell?
Uncle doesn't know, but it's a damned interesting idea. He's never heard of such a thing, but..
..That jackass Dorren is going to hit you with something like that, isn't he? That sounds like his kind of thing.
Also, ask about the possibility of converting the damage type of incoming damage. Is there armour, accessories or magic that can make fire damage count as normal physical damage, or as ice damage, for example?
"That kind of spell does exist. Converting one type of magic damage to physical, or some physical to a certain specific element is possible. As equipment it seems doubtful. As a hitall equivalent spell, something like that can happen. Yes, though, expect one element to one other element."
"Although, maybe a consumable thing could work. Making an item to force someone's fire damage to become ice damage, or to attune their weapon to fire or ice or lightning or whatever.. that should be possible, too.
I don't know if it'd work on Valterre, though. Other people, even other spellcasters, sure, it should work. But Valterre is very powerful and might beat an ordinary consumable messing with it."