Different Dimension Dragon

Edison Card Text
The effect of a Spell or Trap Card cannot destroy this card unless the Spell or Trap Card specifically designates a target. This card is not destroyed as a result of battle when this card battles with a monster with an ATK of 1900 or less.
Dark Crisis • 2007-12-12
No targeting
No Damage Step effect
Banlist • Unlimited
Rulings
edisonformat.net
●Different Dimension Dragon can't be destroyed by Fissure, Mirror Force, etc. Also, if Different Dimension Dragon is your only monster on your side of the field, your opponent can't activate effects like Fissure, Mirror Force, Raigeki, etc.
●Different Dimension Dragon can be destroyed while in your hand/Deck with Chain Destruction.
●If Different Dimension Dragon is face-down, it can be destroyed by Raigeki and similar non-targeting cards.
edisonformat.com
"Different Dimension Dragon" cannot be destroyed by "Fissure", "Mirror Force", etc. Also, if "Different Dimension Dragon" is your only monster on your side of the field, your opponent cannot activate effects like "Fissure", "Mirror Force", "Raigeki", etc.
"Different Dimension Dragon" can be destroyed while in your hand or Deck with "Chain Destruction".
If "Different Dimension Dragon" is face-down, it can be destroyed by "Raigeki" and similar non-targeting cards.