Spark Sliver

: When Spark Sliver enters the battlefield, each Sliver creature you control gains a loyalty counter.
0: Spark Sliver becomes an X/X Sliver creature that's still a planeswalker, where X is equal to the number of loyalty counters on Spark Sliver.
-1: Scry 1. If the card doesn't share a set symbol with a permanent you control, you may put it into your hand. Slivers you control have this ability