astral barrier .. you can get it with R tickets ..i think even log in rewards have it
...
and so far i only lost one and Zane(underground) keep popping out for 6 consecutive duel if you win
tips for this would be spcl summ. BEWD in def mode if you havent got astral yet and attack mode if astral and spirit barrier is in the field ..
..
surprisingly flipping down a monster (kaibaman or DS) while astral is on the field and after using astral on exploder dragon the other monster wont proceed to attack