World tendency

I only play demon souls offline, so how do I shift my world tendency to pure white and then to pure black? And what is character tendency? I'm looking to platinum Demon Souls so I'd like to know more about these.

Can give it a go, though I never understood the difference between character and world tendency. To my knowledge, world tendency is the overall tendency per area for all online gamers (like an average), your character tendency would affect it, if your offline, then your character tendency should match the world tendency (unless there are latent effects if you went online). You can think of each region being on a 7 point linear scale (I think). You start of at point zero, or neutral, killing bosses, or helping coop to kill bosses, gives you +1 for that area, this shifts it up towards the white tendency, with a maximum of +3. Dying while alive or killing other human players will net you -1, or dark tendency, down to -3. Tendency affects the item drop rates and monster difficulty in the associated region. Also, some areas unlock at pure tendencies; for example, the gate at the start of 1-1 opens at either pure tendency, allowing access to executioner Milralda, who is normal in pure white or black phantom in pureblack, providing different equipment (confirm?), also, pure white in world 5-1 gives access to a ladder near the first giant defiled that leads to a super spear.

Hopefully someone with more info comes here soon

Well done berkut, just about summed up World tendency perfectly.

Character tendency is, obviously, the tendency of your character. A lighter character will have more hp in soul form, but less damage.(I think that's the case) A darker character will do more damage in soul form but have less hp. A character of pure white tendency can be given the friend's ring by that old corpse who is a guardian or whatever, whilst pure black will have some old lady who wants various people dead appear. She gives rewards based on who you kill, including the foe's ring. Killing black phantoms and helping other players kill bosses increases the tendency towards white, while killing Npc's and invading other players will shift it towards black. it's advisable to go for white THEN black character tendency as it is easier than the other way around, the same applies to world tendency.

Hope that clears it up.

Character tendency: Raise it by killing red phantoms, lower it by killing NPC's

World tendency: Raise it by killing bosses, Lower it by dying in human form

Thats the simplest way to put it, it takes about 7 eyes of ephermal stones to go from PW to PB world tendency.

You can get PB character tendency way easier than PW so go for PW first, by chaning youe world tendency to black and fighting the red phantoms that appear. It may take 2 play throughs.

It's not really as simple as all that. IMO you'll actually have an easier time accomplishing the world tendency you want playing offline, while character tendency is generally easier to manipulate online. When you play online your world tendencies are affected by the averages of all other players online, but when you're playing offline it will only be affected by your individual actions. World tendency, as has been said already, is affected by things like killing bosses, killing black phantoms, killing primeval demons (as well as whether or not primevals and black phantoms will appear at all), killing NPC's in either of their forms, and dying in body form. Character tendency is not entirely related. It's related in the sense that you're moral actions are connected to it. In other words if you commit "good" acts, such as killing black phantoms, helping other players successfully kill bosses, and kill black phantom NPC's than its moved towards white. Conversely committing "evil" acts, such as invading, killing human form NPC's, and so on, will move it towards black. The main facet of your character tendency is a lot more complicated than that however, and it's what's IMO what makes character tendency so difficult to purposely manipulate. You're SL has direct relevance to your character tendency. In other words if you power level, essentially make your character over powered by grinding souls and leveling quickly, then you use that powerful character to kill weaker enemies, like dregglings, then your character tendency will move towards black. Conversely if you keep your SL relatively low, and are consistently fighting and killing enemies that are a lot more powerful than you, then you're character tendency will move towards white. It's really not easy to find the medium there.

So to summarize world tendency is harder to manipulate online because you're worlds will be affected by other players average tendencies. If you're playing offline it will only be affected by your actions. The easiest way to do this is to commit suicide in the nexus, where your tendency wont be affected, then play the levels in soul form, because if you die in soul form your tendency also isn't affected. Then kill bosses in body form. You not dying and wracking up boss kills will effectively move your tendency to white. Then after you've accomplished any white tendency events that you want, you can return to these levels and commit suicide in body form over and over until you reach pure black. However in order for any world tendency changes to take place you have to leave a level and then return to it.
Character tendency is actually easier to manipulate online, because the easiest way to alter it is to invade, kill invaders, and help other players kill bosses.