Hephaestus is a server for everyone. We have a few plugins but they won't affect your vanilla experience. The ones that may affect a bit are the Bloodmoon in which the mobs are a bit harder but drop better loot, however, if you die to them you'll lose all your items and a plugin that changes the end by adding new biomes and structures to explore.
PVP Will Always Be Disabled. To PVP there is an arena. For that use /duel [username].