That was a bad one. For me, in the first few weeks of release, the very first EG boss, Kasumi, was appearing with 8.7M HP (there were no SEG bosses yet), and the game was spawning in that level of boss TOO SOON for players to deal with it like they can now. Everyone had very low SEDs, but actually they were high for the time. Not sure exactly how low a "high" SED was in those days was...but I do remember that the "Energy Drink" items were only 1K Pero. Even after using one of those, the Kasumi boss required a FULL focus attack from 4-6 of very high SED players, with slayers to kill it. It was pretty bad, the boss didn't have the biggest HP pool, but at the time, it was fucking stupid.