I think somewhere in his lore that he uses blade, and thats why he has them on his arms? Someone care to make a story about them.

Do you have a source for this? I would be interested to write about it.

I think you might have confused the fact that Vladimir used a knife to brutally murder 2 guys.
As for why he has them on his robes,I dunno.

It might an interesting story to be honest because "Tides of Blood' do appear to be swords when you use his ability so yes, I think this might an interesting read as to why they always appear to be swords and not something else

In some of the original art he has these sort of sharpened end caps on his fingers. It originally gave ppl the idea he might be a melee-range nuker similar in some ways to Kassadin.

I can definately see some stories invovling knives and long, long talks about what makes blood so awesome from Vlad's perspective.

Just don't make it "Hostel"-style gore porn okay?