So must it be completed on 1 character?500 THOUSAND monsters killed on 1 char or is it summed up by multiple?
Yes, it must be complete on a single character. It will not be spread across multiple characters.
oh god freakin damnit.any info if the developers going to change it?like in titan quest?
Why? 
It’s an achievement. It’s not something critical to the game. It’s just there as a way for the devs to say “gud jorb you killeded a lot of things”.
well cause some people are perfectionists and like doing things 100%.Like me,I can only get full satisfaction if I get all the achieves,but also don’t want to waste my lifetime on 1 hero.Would enjoy if it were multiple though
One of my chars with 6 days playtime has nearly 300k, so it is only matter of time, keep farming with one char 
Playing for achievements and not for fun IS wasting your lifetime. But I guess you already knew that … 
It shouldn’t be too bad in Crucible. Especially on the easiest of the three difficulties. That’d let you rack up a lot of kills quick.
well sorry for not sharing your superior taste,some people enjoy achievements
well… okay then
Achievements can definitely be done for fun, but there’s always a few of them that take a while to be done. And this is one of them. If this was shared across all your characters, i would have done it twice by now and it would be too easy because of it.
so what you guys think,is there any chance the developers might fix this in the future update?I think they fixed the Titan Quest one that way
There’s nothing broken, so there’s nothing to fix. Honestly, if you think that some achievement is too hard, too tedious or just too stupid, then just ignore it - or pay your price for OCD.
I’m sorry but I don’t see how it could be useful or even just reasonable to tune down achievements.
If they are handed to you on a silver platter then it’s no achievement to complete them.
To be an achievement it has to be something that you have to work for and that sets you appart from others that do not have invested this work.
Most of the so-called “achievements” in GD are already basically given for free and just generically symbolize progress in the game.
Making the few hard to earn achievements less hard to earn would not only make them less of an achievement, it would also piss off those who did earn them the hard way and take away one more goal for those who really want hard to earn achievements to work towards.
You do realize theres a giant difference between hard achievements and grindy annoying ones.I really enjoy hard achievements,hell I love to display them into my steam profile and as much as it too me forever to obtain them I never complained,but this achieve(Ocean of Blood)just isn’t hard it’s annoying,hell I can just turn the difficulty to normal and farm mobs 24/7 but I don’t want that.It would be 10 times easier and less annoying if this would spread across chars,trying every class,building every set.So don’t tell me about this achievement being “hard”.It’s far from it
Then do not try to achieve it, it’s not like you have to or even gain anything from doing so.
It’s still a hard to earn achievement, right?
There may be achievements that showcase your ability to rock the game, there are achievements that showcase how excessively you have played it.
“Ocean of Blood” obviously is one of the latter.
If this would work across all characters it would be simply a matter of time spent on the game as eventually everybody would have it; assuming most players don’t play only one character very excessively but instead rather play several characters less excessively.
This would kinda defeat it’s purpose - that is showing that you have devoted to one character more than normal, having killed an excessive amount of enemies with it.
If you enjoy achievement hunting you are playing for fun. If you aren’t having fun playing the game, you’re wasting your life. #gamerkoans
If you only want the achievements to showcase on your profile, I’m curious as to who you’re trying to impress. Some achievements are fun to hunt down while others are just a pain in the ass. As people have said before me, if you’re not having fun hunting specific achievements, then you’re wasting your time. It’s even more sad if you’re intentionally wasting all that time just so you can throw that achievement up on your profile page so people can “ooh and ahh” at your profile.
Anytime anyone brings up the whole “achievements are fun” argument, I always think back to Dead Rising’s 7-day achievement. Effectively requiring people to leave their 360s on for over 14 hours straight just for a single achievement. Nobody can convince me that watching your health drain away (one block per ~2 minutes) as you stand behind a food court counter can be fun.
Crate already reduced this Achievement from 1 Million to 500.000 in the past. In my opinion 500.000 is ok. I know a few Titan Quest players wich reach one Million kills.