To basically describe this powerhouse of a card, imagine a giant engine that forces your opponent to decide what gets to live and what gets to die, and if killing it is even possible or worth it at that point in time, because even if this guy dies, he gets to bring back a buddy from the Graveyard and protect you even further.
The best use of this card is in Frog-based Monarch decks, especially those that utilize Soul Exchange and Creature Swap for additional removal of the opponent's field and possible threats to Light and Darkness Dragon's survival in battle. Once this crazy, dual-typed deity hits the field, your opponent starts to sweat. If he does have a Spell Speed 3 response to his Summon, chances are his effect to destroy your cards and Special Summon a friend from the Graveyard still activates. But, if your opponent CAN'T stop him, he begins calculating in his own head what is gonna have to go down the drain to bring this monster down. If Light and Darkness Dragon hits the field in the late game, you can pretty much assure your victory.
Strategies and game play:
The strategy behind this beefy negation stick is easy Tributes. This could work with decks that Special Summon a lot, such as by taking advantage of "free Summon cards" like Jester Confit and Fiend's Sanctuary which summon a monster to the field with no costs or restrictions. Also, you could make use of cards such as The Tricky and Quickdraw Synchron that put other monsters in the Graveyard and themselves on the field! Even Mausoleum of the Emperor could be used to get him out early!
Combos with other cards:
The best combo card with this is the universal scapegoat- Treeborn Frog. A continuous Tribute that comes back every turn in a properly built deck. If you want to try some shenanigans, you can try to get Reverse Trap off while he can't negate it, and then continuously activate an effect. He will then climb to infinity attack and defense!
Ways to counteract it:
Easier said than done. Spell Speed 3 responses, such as Solemn traps and Forced Back, will negate his Summon, but those first mentioned will still destroy him. Mask of Restrict and similar effects prevent him from coming out altogether but are difficult to keep on the field considering the amount of destruction typically run in a deck featuring Light and Darkness Dragon. The easiest way to take him out, if you can manage to do it, is build a Chain. Since he can only activate once per Chain, if you use two Bottomless Trap Hole on his Summon, he will be destroyed and banished.
Beating power, negation ability, replaces himself if he dies, not restricted by any ban list limitations.
Relative difficulty to bring out, cannot be Special Summoned, can be stopped by Continuous effects that are already active such as Skill Drain or Light/Shadow-Imprisoning Mirror, and weakens himself over time.
To my knowledge, this card is available in every language from the following packs- Dark Revelation 4, Storm of Ragnarok Special Edition, Retro Pack 2, a Yu-Gi-Oh manga, and a Promotional Pack.
Artwork and aesthetics:
The artwork on this card is absolutely stunning- the duality of light and dark combined with the epicness of a dragon is simply stunning to behold in its physical beauty.
Overall, I would give this card a solid 8 out of 10, a card that has withstood the test of time and though currently under the radar, this divine reckoning force will be here to stop your opponent dead in his tracks for years to come.