i have been to Grizzleheim and i have seen wizards (mostly storm if that changes anything) that can do NATURAL ATTACKS!!!!!!! i'm in the middle of Krokotopia and i still don't have the blade. when do i get it!!!??? (ok so maybe i am not even half way through the game but still...)
The natrual attack you see are what the sword animations look like. When you have a staff or wand, the attack simply hits an enemy with a fireball or etc. But when you have a sword you slash at the enemy with it.
you dont get your first sword until mooshu, but even then you have to be lucky enough to get it from a boss drop. The min. level required to equip a sword is lv 40
with exceptions to the umbra blade which has no level requirement
You mean like when the player vanishes for a second and appears in the middle of the battle circle and then does a flip and kick to the target...(what I like to call ninja kick :P). That type of natural attack I got during Dragonspyre (probably a little late in the game) after I defeated the Hoarder for a quest and I found the Shockblade of the Hoarder (100 storm natural attack plus gives one power pip at beginning of battle) in my loot O:
Then later everyone will get the Dragon Rider Staff (same as Shockblade but in fire) as a reward from a quest later on in DS, but this doesn't give a natural attack :(
Although it is a sword, the umbra blade will not allow you to go to the middle of the circle. It's animation is the same as a wand attack. Thanks, Kieran
i'm in the middle of Krokotopia and i still don't have the blade. when do i get it!!!??? 
(ok so maybe i am not even half way through the game but still...)