The best part of The First Sliver is that when you find a spell with cascade after casting a spell with cascade, that new cascade trigger will happen, giving you the chance to chain multiple cascade triggers with one creature
Energy Switch will come in handy when Meganium isn't available to double up energy, Mega signal will let you search your deck for a Mega ex Venusaur straight away, and Wally's Compassion completely heals ex cards, with energy being returned to your hand only
Perhaps I'm just looking at the best possible scenario for the card, and it'll fail more often than it succeeds, but I'm genuinely a bit worried about it
Dlaczego ANIMATOR Z POMYSEM
For its madness cost you can cast a small 1/1 blocker, but most importantly you can also get rid of one of those big, mean creatures your opponents have on their field