Bloody, pulpy, and solidly photographed, Jalmari Helander's "Sisu" is packed with excessively violent action scenes that manage to entertain. Still, it demands a lot of suspension of disbelief from the viewer to be thoroughly enjoyed. It's "John Wick" against Nazis in Finland, but there is little dimensionality to the characters or pathos in the storytelling. This can be certainly a fun time for kitschy action film enthusiasts, but it almost never tries to be realistic.
The first two or three…