The effect of "Red-Eyes Darkness Metal Dragon" can easily Special Summon this card from the hand. The monster can also potentially serve as a basis for this card's ATK.
This card's effect can be mitigated by its owner protecting their other monsters with card effects, such as "Safe Zone"
In a Hopeless Dragon Deck, or any Deck that relies on high-Level Tribute Summons, "Hardened Armed Dragon" can be Tributed for its owner's Tribute Summons of other monsters beforehand.
This card's effect can be less of a loss for its controller's monsters if they have monsters that have effects that "replace" themselves when destroyed, such as "Lightpulsar Dragon".
Note that in the OCG this card targets its current ATK rather than its original ATK