Yes Luluccia, it takes a very long time. I'm encroaching on Rank 6 and 1-3 took about 5 hours of constant grinding monsters 5 lvls lower. 3-5 took about 25 hours. I'm easily 15 hours into 5-6 and almost there. Even with the choco leeching xp off me, I've still gone from 37-40 just from leveling him. Also... He holds aggro!