So what do these pillars do, exactly? I know that when I have my characters use them, they grant me an elemental shield for that element. (So you could use the statues and move around to the next element when necessary, which should mitigate most of the damage you'd take from Boreas and his minions)
However, that was not really an option because there's elemental effects all over the place. So I just stood in one place and kept throwing aoe to get rid of the minions. It was a tough fight, but we got through it. Having access to all elemental schools is helpful, especially with the elemental shield spells (or immunity to freezing/poison/burning/electrified) and the witchcraft spell 'Absorb Elements', you can effectively mitigate a lot of damage.
Or just make and use elemental resist potions. The materials are plentiful and they add a decent bit of resist.
