If an Xyz Monster(s) you control would be destroyed by battle or card effect, you can detach 1 material from this card instead
While there are other powerful cards like Fairy Tail - Snow or Banishment of the Darklords that offer similar utility and versatility, Keldo's unique effects can still make it a valuable addition, especially in a dedicated build
When the opponent successfully Normal Summon or Special Summon a monster(s), Contact C could be Special Summoned to their field from hand
Since 'holos' are rarer than other cards, if this is what you're dealing with, it's best to look up online which areas of the card should be holographic, and which shouldn't
And if you just want to play normal match types like Standard or Alchemy and build a deck with the odd booster you earn along the way, you never have to get out your wallet or feel like you should, anyway