i have noticed the paralysis too, just stand there doing nothing, i think is because the IA expect to be attacked to trigger the combo, but what happens is an almost dead enemy recharges and oneshot stupid eizo, i think is because the idiot reacts to attacks but never have the initiative.
Its just dumb that she alone is able to take down an entire party, the "attack me if you dare and i'll poison you badly" is broken, first venom is too potent, your life bars gets drained like there is no tomorrow, second, i can understand in fantasy and lore that arachna have poisonous ski...
My favourites ones are: riley, arachna, tareth, xanos, amaterasu (jasmine), dokras, serafine, gale, elric, wraxius (he is my absolute favorite), gizmo, alana, ethera, cara, leah, mortus, osiris... etc, top five? hard to say, but i would say arachna, dokras, jasmine, cara and choose one from the list...
This OP guy cannot be trapped, i tried with Cara, Vincent, Arachna and Dokras, they all have trapping skills to counter high movement characters like eizo or tanya so you can trap them and break their noses with ease, but you cannot trap Xanos as soon as he digs (and he is always digging) he escapes...