One of the best Korean mobile game finally got Global (NA) server! I spend around 8 Months playing In Korean version and currently playing non stop in global version after it been released.
Seven Knights Global Server Guide
Seven Knights (Also known as Sena) is a Tactical Role-Playing Game (TRPG). You can control your characters in all modes except pvp.

Global have 2 servers, NA and Asia. When you enter game for first time it detect your IP and send you to certain server. You can't switch between Asian and NA server.

Almost 1 year old video from KR server -

Difference between KR and Global server -
1. Less characters, maps and gears.
2. Dragon, Raid and Guild War still not open.
3. For some reason in elemental dungeon we can't get 1 star element. They just removed it since it been cheapest way to get elements.
4. No emperors and no board.

Helpful Tips -
1. Between 250 ruby and 30 ruby Gacha always use 30 ruby. It cost a bit more but in the end you get a lot more 4 star characters.
2. You can get ruby by lvling your characters to 30 level. First time you get 5 ruby and then 2 ruby.
3. You can get up to 200 ruby from farm per day if you getting 2 ruby per character. Basically, it 100 mobs per day.
4. If your team weak but you want to farm ruby, farm on 1 - 1 easy mode.
5. Best places to farm is 7 - 1 (can get melee weapon) and 7 - 9 (can get magical weapon) on hard mode. You need strong AOE character (Vellika, Spike or Ariel) and Hellenia. Others 3 teammates must be your 'food'.

Don't skip  "Guide Quest" since it give free 6 star characters in the end.