Oh, Ixidron. I could never stay mad at you.
"As Ixidron enters play" strange and terrible things happen. Never to be cast willie-nillie, Ixidron can do as much damage to your cause as he can swing things in your favor. At the end of a long game, when your brow is soaked in sweat and you hold victory in your grasp, Ixidron is most likely to find some way to ruin everything.
It is important to remember Ixidron behaves less like a creature and more like a sweeper. Instead of some freaky illusion dude, think of him as a three-way cross (pretty gross) between Wrath of God, Humility and Mogg Infestation. All creatures become 2/2 type-less "morph shells" without the ability to ever return to their empowered selves.
Despite the second ability, Ixidron will never get very big. And he gets even smaller. He will shrink every turn as your pissed-off fellow participants hammer your defenses with the flailing riff-raff you've left them with. You either block, or you let them through. I suggest you block.
This method of creature destruction has a couple of unusual benefits. First, creatures are not removed from the battlefield straight away. In EDH, this can wrap up an opponent's general for a couple of turns. It can also keep safe some of the more unusual "goes to graveyard" abilities like the Kamigawa Spirit Dragons. And it even clobbers those indestructible creepies you occasionally run into.
Another interesting aspect of Ixidron is the way the ability is worded. "As Ixidron enters play" rather than "when Ixidron enters play." Standard players have already discovered the difference between these two terms playing against Iona, Shield of Emeria. Creatures are forced to flip over before Ixidron touches the battlefield, and prevents ALL other "when a creature enters the battlefield" triggers.
To be honest, Ixidron MIGHT be a bad card. He has certainly screwed things up for me more often than he has saved things. But considering my play ability, he could just have a bad pilot. The kind of pilot who gets sort of forgetful towards the landing portion of the flight.
Don't play him when he's going to be the only creature on the board. Don't play him when you have 1 creature and your opponent has 1 creature. Unless that creature is like Akroma or something. Did I mention Ixidron makes good creatures into really bad ones?
And when you lay it all out on paper like this, he really does sound good. Perhaps what I've encountered so far is bad luck. So I'll wait a while to see if I get lucky.
One fact is indisputable…when you do plop him down on the battlefield, absolute chaos always descends.
And by chaos I mean FUN. And by fun, of course, I mean chaos.