Blade and Soul is very linear and guides you into content. It has very fun combat, and is very satisfying feeling when you do crazy looking things. I enjoy the theme and the pvp quite a bit but the game just got very boring after 30 or so levels of being guided from quest hub to quest hub doing a dungeon that has three rooms and takes 5 minutes then going back to quest hubs. The gear system is really unique in that you will never replace anything hardly and the only things that effect stats are weapon, jewelry and the armor shards. Your armor is cosmetic and is just there to flag you for pvp against certain factions. I would give it a shot if you are into Korean theme park games or want pvp.

Guild wars 2 is a different beast. It has a very different leveling system where you go from zone to zone exploring to find points of interest on the map and doing associated tasks. The leveling curve is non existent and takes very little time to level even near the max level (80). The pvp is relatively fun if you can stick with the groups in WvWvW, otherwise if you die out in the middle of the map it's a very long run back to them and can be very tedious. The team based pvp is where I stayed most of the time but that isn't everyone's cup of tea. I can't really recommend guild wars 2 after the expansion simply because the leveling of masteries just wasn't fun at all for me. It locked you into areas to hope people would start events with you so you could unlock travel skills to get to other areas and grind more. It was tedious and super boring for me and ruined the game at least for me.

Out of the two I enjoyed pre expansion guild wars 2 a bit better but as of right now I would say try blade and soul. But it's entirely up to what type of game you feel like playing.