Tree of Savior Founder's server OBT started today. Even though cheapest pack cost 10$ (because steam regional price pack cost lower for certain regions) 2 NA servers not enough to handle all this people and IMC Games decide to open Temporary EU Server.
Tree of Savior European Server
Short version - right now EU server will be located in US East Coast and somewhere in the future they will transfer them to Europe.
IMC Games -

We've decided to open a _temporary EU server_ to meet the needs of our players. This server is going to be opened on the US East Coast to temporarily host the players who get better ping from Europe, and then the entire server will be moved to a local server in Europe.

The new server information is as follows:
Server name: Fedimian
Open time: Within 4 hours (we will make an announcement up to an hour prior to opening the server)

In addition, players who have already started progressing on **Klaipeda** or **Orsha** will be given a one-time Team transfer to **Fedimian** at the end of the Exclusive Access period. Server transfer to Europe will be completed in this order:

(1) Take requests from players on **Klaipeda** and **Orsha** who wish to transfer to the temporary EU server (**Feminian**) within a week after our transition to F2P.

(2) Transfer the Teams from **Klaipeda** and **Orsha** to **Fedimian** server first. This may take anywhere from the second to third week of May.

(3) Relocate **Fedimian** server from the US East Coast to Europe by the third week or so of May.

The dates stated are our rough estimates and may change depending on the circumstances.

**Again, this server is going to be physically relocated to our future server in Europe, so if you get better connection from the US East Coast, please do not play on this server unless intended.**

Source.