About Vaal Gems | Is This Intended or Bug ?

So i gotta question guys because for me this seems like a stupid mechanic, or just bug.

1)
So first of all you have a vaal gem equipped. Then you go to a new zone and all the souls you collected reset, this just happens only if you enter a new zone.

2)
Then second, if you have 2 vaal gems, souls doesn't share. Means that if one requires 48 souls and the other 32, you gotta kill 80 monsters and not just 42 for both. Well this seems a bit more logic but still, if your souls reset when you enter a new zone, then having 2 vaal gems it's pointless. I was never able to use any. So i have to stick to using only one.

I'd like to be able to use more vaal gems, they are pretty useless tho, but some of them are actually great as support skills like Vaal Molten Shell.

Still, the first thing i said seems a bit stupid. I think it is a bug. Anyone know exactly what's happening ?

souls are instancebound, if you go out and then go back in you'll still have the old souls