Would rather quietly toil away on my relic than work on EX primals.
Eh, Shiva EX is really pretty easy, though what you get in PF can be a mixed bag I assume, there's people who have cleared it and still suck at doing the most simplest thing. As a DPS especially, it's like herpderp mode. She goes up in the air while spinning? Go to your assigned spot(they're chosen before the pull) and wait for the aoes to pass. 9 icicles nonsense? Find the first one, go next to it, that's where last one is, wait for mid to blow up, run to mid. She was in staff/sword and is going up the air again? That's bow time, get the fuck behind her(which you should be close to anyway if you're meleeing, just stop with side attacks for a second). During bow time, get a blue mark on your head? Get behind her. Screen flashes black? Stop moving. And that's the fight. And all of that shit is really easy to see and do.
It's one of the easiest EX, along with Levi and Mog. Ramuh and Titan are probably the hardest, Ramuh because you actually have to think about what's going on and react as a group, Titan because "OMFG SHIT'S EVERYWHERE".
Issue being, you need all the other EX first other than the 3 originals, so that can take a while, especially Ramuh. Don't know the state of the FC you're in or what though, we do primals carries every now and then. It's very easy at this point for 7people to carry a corpse through any of the content up to final coil. Hell I'd say you could do it up to T12, at which point I'm not sure if you can make the DPS checks even geared. Maybe.
Otherwise you can continue your relic I guess, but books are shit. Getting a 110weap from soldiery is an option, that's something and it's easy to get. I assume next patch they'll add welfare weapon drops for poetics weapon, but you'll need 1300poetics which takes 3weeks of poetics to get. That'll be 120 though, and they'll probably add a better way to get carbontwine too(atm you need 3000allied seals from hunts which sucks) to upgrade it to 130, which is basically, 2nd best in the game.