In one of the Initiations for the Bjornaer Clan Maruhs, it says that the magus must be bound in magical chains and cast into a pit, and escape. This Copperfield trick earns him the Puissant Art Virtue but he also gains Unpredictable Magic. But the question would be what kind of chains these really are? What should their effect be?
E.
Depends what art the virtue would be in? maybe for ignem chains of fire (may or may not burn), terram is normal chains, animal are strips of hide, ect...
Once you decide on the chains, any effects may be easier to create.
Good point. But it will be Aquam, as my Bjornaer is an Aquam specialist. Ice then, maybe? Chains of ice, that sounds cool. 
E.
I shall craft for you these chains, oh Master! For a suitable vis fee of course... For an added charge of no more than double the original amount, i shal even make them breakable...
No, no.. they shall not be breakable. You shall use all your power to create a chain my character can not escape from. And if I do escape, I won't have to pay you
E.
I shall forge a chain out of the sound of a cat's footfall, the beard of a woman, the roots of a mountain, the sinews of a bear, the breath of a fish and the spittle of a bird.
I don't see you breaking out of it anytime soon. 
But seriously, how about coming up with some examples on how to make magical chains for this Initiation into the Clan Mysteries? Let's see some rules
E.
The Bjornaer in my saga has just passed this rite. He got bashed over the head in his sleep, stripped naked and bound in heavy chains sealed with 4 large and sturdy padlocks. The chains are enchanted to stop him from shifting into heartbeast form.
He was then dumped into a 20' deep and 15' diameter pit.
The character managed to get himself out by melting the metal of the locks. This of course gave him severe burns on the first one and it was thus a test of will (and the ordeal) to summon the willpower to melt the others knowing the burns he would suffer. After free from the chains he blast the pits wooden cover off with a PeHe spell and flew out in Bird form (he is a prodigious shapeshfter). Out of the pit, the whole of his clan were waiting for him to calm him down and clue him into the rite.
Well, in my campaign, this rite would happen when the Bjornaer himself feels prepared for it. I think an important part of these challenges is that the Magus must put himself in harms way, as a test of willpower. These tests should, in my opinion, happen when the Magus says he's ready.
E.
That doesn't mean he would know precisely what he's getting into. That's why they are called Mysteries. If he were told in advance "we'll chain you up and throw you down a pit", that blunts the psychological effects of the ordeal, which might well cause it to fail: "we can't tell you or it won't work."
Well, I disagree. If the ordeal is terrible enough (compared to the virtue granted), I think the Magus should decide himself. It has something to do with mastering your own fear. I remember my first parachute jump. If someone had thrown me out of that plane, it would have been easier, as I would have had no choice but to do what I had learned to land alive. But the real challenge was to step out myself, know that I could tell the jump master that I didn't want to do it.
I think it's the same with all the Ordeals I can think of from Mystery Cults. It is up to the Magus.
E.
Indeed I can see your point. However the only part of the ordeal that the mage wasn't party to was being trussed up and chucked in the pit, not so terrible. Having to inflict very nasty liquid metal burns to himself, repeatly, to escape, now that was the ordeal. The idea was that the magus was perfect aware of what he had to do to escape the chains. But to do it would cause him terrible pain and injuries.
Also, his clansmen did not simply kidnap him. He spent many hours talking to the head of the clan (something Egg-Thief) in what he thought was innocent conversation but was actually a test of his character and determination. Eventually he was asked if he wanted to learn more about the secrets of his clan. He was warned that not all of it would be good and there was significant risk. He simply wasn't provided with the timing or nature of the ordeal first.
Needless to say, when he escaped from the pit he was ready to kill someone but his clansmen calmed him down, healed him (although he retains funky scarring) and helped him understand the ordeal.
But the chains you mentioned seemed to interfere with the Limit of Essential Nature... And seeing as Bjoernar can use a Stamina + Hearbeast Ability to change their shape no amtter what, I'd have to set a difficulty that would be both silly and "fake". (As the Beta Boss I'll be doing the ruling at that time...) Thus I'm thinking chains that change WITH the Magus. While he's in human form, the chains are sized for a human, if he was in Otter form, they would change to fit that shape as well. A set of chains that would enlarge or shrink to fit any and all target beetween Size +3 and Size -7. They would also have to be immune to fire me thinks, and prodigeously strong...
But would it be enough with a ReTe(Mu) effect, or would it have to be a ReCo(Mu, An) effect? And how would i hinder Penetration rolls? Can one add "illusion" levels to increase the difficulty of Penetrating the Effect?
I'll post a suggestion later.
This sounds interesting. I don't want this to be too easy, so go for it. Now the rules doesn't state that the Heartbeast Ability can be used to throw off these chains, but I would say that they can be used on any magic that tries to prevent the change (Sta + Heartbeast with difficulty 3+Magnitude). I would love to get an official ruling on this.
So for the chains to a challenge, they would have to change shape with the Magus. Any suggestions on how to build this?
E.