Banish "Koa'ki Meiru Drago" and Summon "Red-Eyes Darkness Metal Dragon", especially if there is another copy of the former in your Graveyard to revive with the latter. WARNING: Since "Drago" disables the Summon of DARK monsters, this strategy only works if there are potential targets for this card that are NOT LIGHT or DARK.
Banish a "Dragon Ruler" monster with this card to not only Special Summon another Dragon from your hand, but to also add another one from the Deck to the hand.
Be sure to use this strategy on a different turn than one when the effect of the "Dragon Ruler" monster is used. This is because each "Dragon Ruler" can only use one of their effects per turn, including the one that activates when the "Dragon Ruler" is banished. The best time to use this card to banish the "Dragon Ruler" is most likely during your opponent's turn before the End Phase unless your "Dragon Ruler" is Summoned without using its own effect.