Tanking EDP SB in PvP. Good luck with that. Even average SinX can oneshot pretty much anyone.
Elements, guess them correctly.. know who you're playing against.
It's not that hard to read your average opponent SinX. They will almost always poison or neutral. It changes ff they throw in verters, tag respectively, this is where most of the guessing/knowing comes into play.
I can't say I've mastered reading my opponents 100%, but most of the time I can call it right, it's not like im just bluntly tagging to a random element, you just gotta keep in mind what element your opponent favors most of the time and why.
tanking off wind endowed SB while being frozen simply because you tagged to a wind muff is another example.
It pays off to practice switching elements and I dare you to play vs a wiz without tagging elements properly. Same for sinxes, if you don't have swall you gotta do something.
Link + EDP is too OP though, no chance in hell you can tank that as a sniper.