Japanese Number Cards

I've started a new blog (here) about how to play Magic the Gathering in Japanese. Only a few posts are up at the moment, but I hope to update it with new content daily.

In that blog, I use custom magic cards based on Japanese words to make them easier to remember. I'd like to re-post some cards based on Japanese numbers here.

While the card names are based on puns with Japanese numbers, I want them to stand on their own as Magic cards rather than just be memory tools. I welcome any critique and suggestions on improving these cards.

The goal is that they will be fun and balanced enough so that if anyone wanted to actually play with these cards in a cube draft that mixes real cards with fan cards, the players who aren't interested in learning Japanese would still welcome these cards' inclusion.

Here's the first card:

This represents the numbers 1, 2, and 3, and it has to use those numbers somewhere in the text.

Flavor - The Itchy Knee of the Sun is a knee-guard that grants the power of the sun, but makes the wearer so itchy that he or she is forced to crouch down and scratch him/herself.

Flying + lifelink is often broken in limited, as Vampire Nighthawk has taught us, but I think the fact that it requires this card + the cost of tapping two creatures (except for the first time you attack with it) + 3 mana every turn in order to get a lifelink attacker will make it ok.

The left side signifies the number 4, the right side signifies the numbers 5 and 6.

The right side, Go, Rock! is almost the same as Stone Idol Trap, but the target Mountain becomes an Elemental until the end of your next turn, meaning that if you cast it on your turn, you get to attack with the Mountain twice. I wonder if that wording is too subtle. I couldn't come up with another way to make the right side balanced with the left side.

This represents the numbers 7, 8, and 9. Since I chose to use the number 7 as the cost, I needed a powerful effect to match that cost.

Flavor - A cube that incubates banana cells to hire an army of mercenary Apes.

This is what it looks like with reminder text:

The last card is this:

This represents the number 10. I wanted a big effect for fitting of 10 mana, but something general enough that you could build around it with the contents of a draft cube.