I've tried Skill Drain in Classic Blackwings, and it does work. The effects of a lot of Blackwings aren't that important and Skill Drain, while it does hurt Blackwings, doesn't hurt them to the extent that it kills the deck.
Many decks find that Skill Drain completely murders them.
Shura the Blue Flame is used at Attack points. The effect is purely a bonus
Bora the Spear is a level 4 monsters. The piercing damage isn't really needed and Skill Drain doesn't hit his special summon effect
Blizzard is hit, so true, Skill Drain is a hurtful card
Gale the Whirlwind. Special Summon effect isn't hit. True, the cutting attack effect is hit, but it doesn't become important with Skill Drain. Synchro Summoning more powerful monsters is what they do
Armor Master: He's intended to be a beater. True, his effect is pretty good, but a lot of other monsters find ways over it, or he's just straight out killed by the effects of cards such as Absolute Zero or Master Hyperion.
Silverwind the Ascendant: Good effect. But gets a bit tricky to summon into. Many level 8s are run over him. He's just the Vayu target. Besides, his attack points are good enough to keep him as it is
Armed Wing: Can be sided out for stuff such as Gaia Knight the Force of Earth. Not really that helpful
Zepharos the Elite: Effect not hit by Skill Drain
Overall, pretty good card to run in the deck. Just make the Synchro monsters more attack oriented, and you've got the match in the bag.
Just my two cents though