Slick blue scrabble pic - courtesy eric - corgilabs.

Employing Halpern's Skip Method

Borrowing skip method, we can create 4 kinds of wildcard based on style.
the first card is || - any radical that can be put side by side
the second card is 二 - any radical that can be put bottom up
the thirdcard is 回 - any radical that can be put inside outside
and the last card is 焉 - any other radical that can not be part of above styles.

ax