I'm sure most have come across those daddy long-legger looking spiders by now. Using a simple tactic, you can take down red shield Yarzon!
Save you weapon skills. When you see a purple-ish light appear around their mouth, move around behind them. This signifies they're ready to use Corrosive Spit (which they tend to spam). The thing about the attack is it's a cone attack. If you're behind them, you can watch the attack hit the ground leaving you unharmed. Once behind them, let loose a weaponskill and stay on your toes for the next Corrosive Spit.
Their normal attacks still can hit like a truck, so two or more forms of cure are suggested.