As with all plant summons, it is unable to move or attack directly, relying entirely on its abilities.
CursedPlants will most often be seen if there's a Ghost Plant on the field, who have SpawnCursedPlant as a fixed skill. CursedPlants only get two support skills, but their true usefulness comes from their ability to SpreadShadow every turn. Combined with the fact they can be spawned anywhere, with the target tile turned into to shadow, this makes them a very effective way of turning the field into shadow for a shadow team. Just keep in mind they have a maximum range of 5 that they can terraform, which makes them less effective on larger maps.