That's the part that confuses me. Mullvad has distanced itself from his stance. As for the party..:
My analysis
The party he supports has been claimed to be Marxist, and elements of that can be seen in it favouring a 30-hour workweek, strong secularism, making public transit free of charge, as well expanding social housing.
However, it (falsely) aligns workers with the business class, thus showing elements of favouring the bourgeoise rather than the proletariat; it also is nationalist in character, rather than internationalist, and wishes to deport fellow labourers. Moreover, it disfavours green energy and is thus a tool of the global capitalist coal and petrol companies. It also opposes liberating the worker from gender-based negative discrimination, because it wants to abolish quotas.
Since their policies don't support inherent change of power structures, nor liberate the worker from discrimination, I would label them as revisionist marxists due to their alliance with the oligarchs.
Proton on the other hand, has confirmed donations that tend to be for organisations which I'd label as broadly progressive, but generally towards the centre-left. However, their CEO is obsessed by AI and has supported a statement of Trump. So it's really crazy.