I'd still say sell Ledger Shredder - especially now that it's $25 - but I also thought that was the best move when it was $10 or $15, so who knows at this point
If you do go deep on dungeons, I would run Thorough Investigation for sure, as itll help you to fine-tune finishing a dungeon so you can dive into the Undercity as soon as possible
An additional 16 winners were given the card a year later before the Pikachu promo was never made again
The order of the colors doesn't matter, so the effect will activate for either yellow and black or black and yellow
If the equipped monster would be destroyed as a result of battle, destroy this card instead, and make the Battle Damage to the controller of the equipped monster 0
Granted, those decks are almost all focused on milling out the opponent but the original Hedron Crab is also able to target yourself, which makes it one of the most explosive and mana-efficient self-mill engines ever printed