Steam & Fury is held at Hotel Vallonia in Mustasaari Finland. Mustasaari is a small village close to Vaasa at the Western coast of Finland.

Getting to the venue will require some planning and my advice is to make those plans early as flight fares tend to raise steeply the closer to a specific date you are doing the reservations.
Vaasa has an airport (VAA) and there are direct flights there daily from Helsinki (HEL) by Finnair and Stockholm (ARN) by SAS. Vaasa airport is 15minutes drive from the Venue.
Other option is to get a flight to Tampere-Pirkkala (TMP) airport and take the train from Tampere to Vaasa. Train takes roughly 2 hours and there are several trains going daily. At least Air Baltic offers flights to Tampere either directly or via Riga.
Flying to Helsinki (HEL) is also a good option. There are several trains coming to Vaasa from there daily and it will take around 4 hours, Trains in general are good and on time in Finland, also they are quite cheap if you book the ticket early.
All trains in Finland are operated by VR. Schedules etc can be found: https://www.vr.fi/en
If you like driving then one additional option is get a ferry from Stockholm to Turku and drive from Turku to Vaasa. Vikingline, Silja-Tallink and Finnlines operate several daily ferry connections on that route, but this will take a lot of time to execute and usually flying will be cheaper anyways.
There is also 3 hour daily ferry connection to Vaasa from Umeå, Sweden operated by Wasalines.
And the extremest route is to drive around Gulf of Bothnia….