Like most Magic: The Gathering cards, the value of Angelic Skirmisher depends on a few consistent factors: its rarity, the printing and finish (regular or foil), its physical condition, and the set it was printed in (Gatecrash)
The idea is to use this effect to put our opponent in a compromising position , which opens the door to several possibilities, such as Forcing them to retreat a Pokmon that has no Energy to attack or a high retreat cost, allowing us to attack and steal its Health for a long-term advantage
If we do get some further benefits for spiders, then Chainweb Aracnir will potentially overtake Kraul Harpooner as greens cheap, main deck defense against flyers
The latter is, just like in the games, an intimidating dragon with a suite of powerful effects including its Mega Flare finishing move which could wipe out your opponents in one go