Xyz vs. gravity bind/any level lockdown card

here's the situation: me and my buddy are dueling IRL and he's got Gravity bind on the field. I Xyz summon Utopia to attack him, he says I can't because of Gravity bind, I tell him I can because Xyz monsters have RANKS instead of LEVELS.

He had two arguments for this:

1. Because Gravity bind, Grave of the super ancient organism and so on came before Xyz monsters, they are still affected.

2. Ranks and levels are both in the form of stars, therefore they are the same.

Now, I don't have to tell you how completely ridiculous these "arguments" sound but because I go to school with morons, I need a second (and maybe a third, for good measure) opinion. Preferably from an admin.

so tell me, who's right?

You're right. See on Yu-Gi-Oh! Zexal episode (forget, Shark vs III). Xyz monster doesnt have Level, that why Xyz monster can't be used for Synchro. Gravity Bind said, "Level" instead Rank. The reason why this card unlimited cos Xyz monster doesn't have Level and unaffected by Gravity Bind, Level Limit, etc

You are correct. Gravity Bind does not affect XYZ monsters because they don't have a level, they have a rank. So yes, ranks and levels are different.

You should really start using google dyce man. You can certainly find rulings all over the place that state you are correct.

Thanks everyone!

Directly from the source in case you would need proof:

http://www.konami.com/yugioh/articles/?p=3154

If you want to Summon a lot of different Xyz Monsters in one Duel, you’ll definitely want multiple copies of Gagaga Magician in your Deck. Rank 3 and Rank 4 Xyz Monsters are already easy to Summon, but if you combine Cyber Dragon with Gagaga Magician you can play Rank 5 Xyz Monsters as well! You can also use Gravity Bind and Level Limit – Area B to protect yourself from attack while still being able attack because Xyz Monsters don’t have Levels and aren’t affected by them.