These are simply reskinned cards from Tales of Middle-earth made to look like theyre printed on an aging scroll of paper
A mean little trick if your opponent hasn't seen the card and asks what it does, just say, You'd better read it. Who/What/When/Where/Why The split cards were originally in Unglued II
Back in Innistrad Sorin created both Avacyn, the guardian angel of the plane, and the Helvault, a prison to trap demons
If you want to buff this Commander Deck, other cards that make artifacts hexproof and/or indestructible could certainly be very fun, as barring a board wipe, this would prevent most damage, and help to keep your Commander alive, and annoying
You won't see Griselbrand coming back from the graveyard in Commander, though, since it's banned in EDH