The Stormblade is a variant of the Shadowsword, which replaces the Vulcano Cannon with a Plasma Blastgun, thus turning it into a more battle-ready variant being able to fulfill several roles on the battlefield, countering other super-heavys and large infantry armies with ease. It can even be used as a Titan-Counter to some degree, since it's Plasma Blastgun is capable of much higher raw damage output against Void Shields. The secondary armament consists of Heavy Bolters and two Lascannons, making it much more indepedent of close-range support screens then a Shadowsword.
Stormblades are also extremely powerful offensive tanks, shredding large mobs and most vehicles with ease, and thanks to the long range of its main armament can even stand against stray aircraft as long as they dont amass, since a direct from it's main gun is almost always a death sentence to most aircraft. The relatively slow speed of the Plasma Blastgun however, compared to Twin-Linked Battle Cannons, makes the Stormblade vulnerable to fast rush attacks.
While it is tempting to form a frontal assault with these beasts at the tip of it, it is better to keep them a little behind the frontline, since they are not as armored as other Baneblades and prone to get swarmed. A good way to use Stormblades is to have them crawling right after the linebreakers, clearing out any leftovers whilst protecting either Shadowswords or small titans from getting swarmed or flanked. Be aware though that Stormblades still suffer from the drawbacks of all Baneblades, albeit its long range and devastating main gun make up for it.