Ice Release: Ice Rock Dome of Magnificent Nothingness

Haku can quickly freeze the surrounding air and create an ice dome around his allies and himself to act as a defence. It is strong enough to withstand the assault of many explosive tags at once, (only slightly damaged in the anime).

Trivia

 * is written with the kanji for "Magnificent Nothingness," but, when written in katakana (ドーム), it means "dome".