This card cannot be destroyed by Spell/Trap effects that do not target it. This card cannot be destroyed by battle with a monster that has 1900 or less ATK.
Rulings
Individual Card FAQs
"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.
Netrep Rulings
If โDifferent Dimension Dragonโ is the only monster on the field, monsters with 1900 ATK or lower do not attack directly.