The only realistic out is mourner drawn for turn, because no way they're holding it during your combo
For our full ranking of high-value Japanese cards, see the most valuable Japanese Pokemon cards guide
The Continuous Spells can only activate this effect in the player's Main Phase, while the Continuous Traps can only do so in the opponent's Main Phase
The tip of his tail is actually white in this image, but that appears to just be a highlight
Special Summon 1 monster from your hand, Deck, or Extra Deck that has 2 or more of the same Type, Attribute, and/or ATK (but negate its effects), and if you do, negate that targeted monster's effects, also, after that, if these monsters have the same name, you can banish both, face-down
The power levels of each Commander deck vary, with some on the weaker side and others fantastic right out of the box