Gladiatus is a great pvp web browser game, best I've see

Stridar

If you haven't tried Gladiatus then you should give it a go, you can log in just a few times to run a quest or two and train or when/if you have time you can stay at the computer and play actively, depends on how hardcore you want to get.  But it's great fighting other players in the arena to lvl up.

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