@neill1990 & @Bleeny - the Challenges achievements were set based on where players already are in the game, just like the others. It's definitely a big challenge to reach the highest tiers but we didn't want to leave anyone without something to aim for. And just to clarify, the changes to Energy and Stamina (in some other games) were not intended to make the achievement tiers easier per se but to incentivize people to invest in Attack and Defence instead. Tons of energy or stamina aren't a big help if your character is too weak to compete with players in your level range, and with the cap especially, at a certain point investing in Eng. and Stam. give diminishing returns.