Ice Release: Ice Rock Dome of Magnificent Nothingness

Haku can quickly freeze the surrounding air and create an icy, transparent igloo-like dome around himself and/or allies to act as a defence. It is strong enough to withstand the air assault of many explosive tags at once, remaining almost undamaged.

Trivia

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