Hi there,
I´m really enjoying this game, but I have a LOT to learn about the new cards (and rules, too).
New for me is anything past Manalink v1.32 and 4th edition rules.

Unpatched Manalink 2.0 alone has 337 cards that were new to me!
I finally managed to beat Tribal Trials, using this deck:
;Angelic Strike
;First Strike White
;Underdogs
;no.spam@plea.se
;24/02/2010
;1
;4th Edition
;
.188 15
Plains.167 1
Mox Pearl.17 1
Black Lotus.157 1
Mana Vault.221 4
Serra Angel.816 4
Thunder Spirit.862 4 Rainbow Knights
.64 3
Disenchant.240 4
Swords to Plowshares.794 3
Spirit Link.290 2
Wrath of God.1198 1
Akroma, Angel of Wrath.159 2
Meekstone.726 3
Moat.806 2
The Tabernacle at Pendrell Vale.166 1
Mox Jet.216 4
Scrubland.230 1
Sol Ring.62 1
Demonic Tutor.694 1
Karakas.333 1
Vampiric Tutor.508 1
Mishra's FactoryNothing new when it comes to the key cards to battle the fast creature decks in this challenge. The deck evolved from one of my favourite and most stable Shandalar/v1.32 Gauntlet decks. At first, it was illegal (immediate auto-loss) and I didn´t understand why. Turns out
Mana Vault is restricted (I had 3 of them)...
I think I made 30 or so attempts in total, 7-8 of them with the final version of the deck. The third time I made it to the Sliver deck, I won. I had really crappy starting hands the other two times.
I have a good record against the Fairies deck. A reasonably early
Thunder Spirit or
Serra Angel keeps the Fairie Rogue swarm from attacking. I could sometimes win without an early Tabernacle, but it was an immense help the times I had one.
These three duels from my succesful run are the most memorable:
Rats: I had four lands and a
Moat in the starting hand, but I was almost killed before I could cast it. The rat deck got a great draw, and it really is
relentless.

It took a
Swords to Plowshares, a defensive
Spirit Link and a heroic sacrifice of Knights to have me survive to the fourth turn!
Soldiers: I got the first move, but had no Tabernacle in the starting hand. No land either, but I had a
Mox Jet, a
Vampiric Tutor and a
Moat. I tutored in
Black Lotus on the first turn and cast
Moat on the second.
Slivers: I had the first move and Queen got killed by a first-turn Tabernacle. Still, I was almost ran over a couple of turns later, and I was actually
saved by a
Sinew Sliver that gave some attacking slivers at least 3 in power, which meant they stopped untapping because of a
Meekstone I had in play. I was now down to 1 life. I summoned a
Thunder Spirit that gave its life to stop that
Sinew Sliver (all slivers were flying at this stage). Some Spirit Linked Rainbow Knights (protected from blue) won the duel for me a couple of turns later.
(Interesting fact: my deck has 3-0 vs the Soldiers deck and 4-0 vs the Elves deck. Probably mostly due to luck with the starting hands but it´s still cool.)
Winning this challenge "unlocked" a card for me. I have some questions about that:
* Are "locked" cards unavailable in regular Gauntlet, Duels and Sealed Deck tourneys also?
* Can they still be seen in the Deck Builder? If yes, how can I know which cards are locked and which are available?
* What happens if I put a locked card in a playdeck? Will I auto-lose all duels, will the locked cards be switched for something else (basic lands?) or will they simply not be possible to cast?