The Umbreon Ex card is no different - harder to pull and stronger to play than your regular Umbreons, it's naturally going to have some value
Kaito, Cunning Infiltrator has a few things going on for it, notably that you can give a creature unblockable and profit from your creatures hitting your opponents
Where the binomial distribution tells us the probability of getting a specific number of successes with replacement (i.e., equivalent with shuffling your deck, revealing the top card, noting whether its a land or not, then shuffling again and repeating), the hypergeometric distribution takes into account that card draws are, in fact, not independent (i.e., telling us the probability of getting a specific number of successes without replacement, where cards arent reinserted into the deck after being counted as a success or not)
While they don't help us fill our graveyard like Faithless Looting or Ideas Unbound, they are pretty good at churning through our deck to find our combo pieces
Trainer & Supporter Cards Offer in-game advantages like drawing extra cards, healing Pokmon, or manipulating energy placement