I just started playing and I really want to be a necro for RP sake, but the mechanics seem very anti-fun, it's just too punishing, yet the class isn't very strong. So we have to be in a graveyard to summon our skeletons, which means if one dies we gotta run back across the map or sometimes an entirely different map just to summon them.
My suggestion is simply changing it from 3 graveyards to 1 graveyard.
I'm not entirely sure on late game balance, I've asked around and was told it's bad, I'm only lvl 25 in necro so far. I just think it should be somewhat fun and not so tedious. I'm sure there's a ton of other suggestions about balance, maybe adding in spectres, or the ability to make a golem or homunculus from body parts we collect, I think that'd be cool.
Anyway, that's just my feedback for this class.
update: Lvl 35 now, the class has just felt so incredibly weak the entire time. I can't really solo anything now, where as sword/psychology let me solo pretty much everything at my level. Currently playing as fire/necro, I'll try spider/necro soon, regardless, the minions are super weak in all regards, hp, dmg, AI, etc. In the future I'll level bard and druid to try with it too.
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On another note, this game seems to be getting a lot of new players and dungeons are becoming overcrowded, I had a suggestion for this too. Without forsaking the open-dungeon aspect, and without making it impossible on solo players with spawn-rate increases, I think the best solution would be to have a 'channel-server' system for dungeons, so when you enter you can choose to switch channels to another one if the first is overcrowded. This will eventually be necessary if the game becomes very popular, it's already becoming an issue trying to farm or simply do quests in lower level dungeons.