Decks Using This Card:
* <a href="http://elementscommunity.com/wiki/decks/mono-darkness/">Mono-Darkness Deck</a>
* <a href="http://elementsforum.co.cc/index.php/topic,17436.0.html">Vampiric Dragons</a>
Black Dragon is one of darkness' only heavy hitters, making it a valuable card for damage in mono-darkness decks. At 10 attack (12 attack upgraded), Black Dragon trumps every other darkness creature for brute power (the second highest attack creature in the darkness series is Gargoyle, whose attack is 5 unupgraded and 7 upgraded). This fact alone makes it fairly essential to mono-dark builds.
When playing in an upgraded environment, it's important to note key differences between Black Dragon and Obsidian Dragon. Things to consider between the two include quanta cost, attack power, HP, and the effect of Gravity Shield. Black Dragon costs 2 quanta less than Obsidian Dragon, allowing it to be played sooner than its upgraded counterpart. However, the increased quanta cost grants Obsidian Dragon 2 more attack and 1 more HP, making it a heavier hitter and more durable creature (for example, it'd take 2 Lightnings to kill an Obsidian Dragon as opposed to just 1 for a Black Dragon). With increased durability, though, comes the price of losing the ability to pass through Gravity Shield, as the shield blocks any damage from creatures that have more than 5 HP.
In short, it's a matter of playstyle; it's the choice between a dragon you can play sooner and can bypass Gravity Shield vs. a slightly pricier dragon that can hit harder and last longer. (Note: A player shouldn't forget about the effects of Nightfall/Eclipse, as playing the dark permanent will increase a Black Dragon's HP to 6 and therefore lose its ability to pass through Gravity Shield.)
Even though 10 or 12 quanta may seem like a big price to pay for this creature, pillars/towers alongside Devourerers/Pests will build up the necessary darkness quanta in no time. When coupled with Eclipse, Obsidian Dragon becomes a humongous 14|7 dragon, with the only higher attack creature being Ruby Dragon (15 attack). Because of its high attack and decent HP, Black Dragon/Obsidian Dragon can be used with Liquid Shadow, which not only damages the opponent, but heals you for a large portion of your HP (just beware that your dragon will eventually die because of poison).