Let's look at some of the common rookie mistakes that I've posted on the column and is shown here:
Minun: I don't know, I personally think YGO has less space for effects text than Duel Master and Magic (and pokemon), so the average length of the effects text is shorter. Fir you'd be saying stuff about Black Luster Soldier and the like that has 4 font that crams every single bit of info into the tiny little box: does it really look that good?
This is what we call "add-on" or "random hosing" (hosing means essentially being really good against something). Generally we like to avoid this all together unless it's a REALLY big hoser (i.e. colour/element hoser).
O, and Ham warrior has a weird text that needs some clearing up on.
Overall, it's a very good start and I'd like to see some more stuff from you.
Yamichi: Excellent effort, I did notice that you can most likely shorten your wording here and there to make your cards sharper and more concise. Aside from the long wording issues, I don't seem to see may blindingly horrific problems (I do know the probability of getting the combo itself out, so I let it off some slack).
Digivirus (whoa, cool name if you shorten it): The Legacy Weapon EH. lol I don't thinkg mounting up 25 mana is going to be easy, and with the mana requirements too for its activation. I have a concern of it being too...costly and nobody will even take a look at it, tho.
KLS: No...comment (aka stupid unglued cards. lol).
Okay, here's another card of mine for magique: the gathering
Creature - Merfolk
Seascraper is unblockable
It's an interesting setup, and I'm debating on whether it should be shockable or not. This is the "not" version, the other would be 3/2. I've tried testing it in this format, and I think the power level might be a little high (blue standards for creatures). Further testing might be required.