While known for mods, Mod DB hosts "Save Game Packs." Search for "Diablo 1 Ultimate Save Pack." These usually include 10+ characters with different builds (Mana Shield Sorc, Berserker Warrior, Trap Rogue).
Specifically for the Diablo 1 HD Mod (Belzebub), this site hosts compatibility saves. Vanilla saves often crash mods, so always check if the save is for "Vanilla," "Hellfire," or "Belzebub." diablo 1 save file download
The community is small but active. Users frequently share Google Drive or Dropbox links to their personal save collections. Look for pinned posts or use the search function: flair:save file. While known for mods, Mod DB hosts "Save Game Packs