So, i was thinking and i came to the conclusion that the Eclipse was, really, a good thing. Let me explain. For one part it gave us the whole revenge/I want to kill everything that moves angle. Griffith got the tools (AKA The power) he needed to fullfill his dream and Guts got a goal in his life. That's what shocked me the most. I now remember that Guts was a guy who was lost in his life, just like he was living aimlessly before joining the Band of The Hawk. When he decides to leave, for a time he is again lost. With a really vague definition of his goal or dream. If i remember correctly he: a) wanted to be happy and b) wanted to be like Griffith, so he can talk to him as an equal. Well, the Eclipse fixed that. Now he has a well defined goal in life: To kill Griffith. He has been trying for many years now, i dont know what would happen when he finally manages to do so.
So there, the Eclipse was good for everyone... Well except for the guys in The Band of the Hawk who got turned into a quick meal and of course Casca, who got fucked (literally).