Here, in chronological order, are all of Shishiwakamaru's attacks:
Incomprehensible Speech: The first and most deadly of Shishiwakamaru's attacks, by which he obfuscates all he does and completely confuses the translator. Until such time as I know enough Japanese to get through his dialogues, the official explanation is that Shishiwakamaru speaks in samurai Japanese.
No, really. Samurai Japanese. That's the ticket.
Shide no Hagoromo: The Cloak of Death. With this floating veil, Shishiwakamaru envelops his opponents and sends them off to another place--maybe even another world. Not even Shishiwakamaru can tell where they will go. There doesn't seem to be any defense against the Cloak of Death, except to avoid it altogether.
The impressiveness of this excruciatingly bishonen attack is weakened a bit by the fact that when Shishiwakamaru used it on Kuwabara, Kuwabara blipped across the vast expanse of space and time to... the old arena, a couple of miles away. There death awaited him in the form of his sister Shizuru. She did a good job, but really, Waka-sama, you can't count on all your opponents' having a scary oneesan.
Translation notes: The kanji for the Cloak of Death literally mean "the angel's raiment of leading into death." In effect, the Cloak is a psychopomp. (Look it up?)
To power up, Shishiwakamaru draws the two halves of the Wailing Vorpal Sword's hilt apart, revealing a core of melted, groaning skulls shaped from pink ooze. These belch forth glowing spirits which circle the Wailing Vorpal Sword and add to Shishiwakamaru's power.
When Shishiwakamaru twirls the Wailing Vorpal Sword above his head like a baton, its piercing moans make its listeners double over in agony.
Bakutodokushokusou: Roughly, the "split open and vomit forth skulls which bury whatever they touch" attack. It does exactly that: When the Wailing Vorpal Sword hits, the explosion of raw ki splits open the ground, and howling skulls fly out of the blast and start eating whatever they touch. They have a fondness for heads. In the manga, Shishiwakamaru either can't control the heads, or doesn't bother to control them. In the anime, he can choose to direct them in order to concentrate their attack.
The Bakutodokushokusou takes enormous energy--even Shishiwakamaru is drained after he acts as a conduit for it.
Translation notes: Translating this attack name has given me a headache and a half. It appears only in the anime, and my copy is a) cut off at the bottom, so that I can see only the top half of the kanji; and b) in raw Japanese, so I don't have a translator's input. The best translation I can come up with is the "wall which calls upon resentment to bind and harm." Mind you, it could also mean "wall which calls upon mandarin ducks to hinder and win esteem." Either way, it's not catchy.
Tameshi no Ken: The Sword of Trials or the Test Sword. After the end of the match between the Urameshi team and the Uraotogi team, Suzuki gives the Sword of Trials to Kuwabara. It's just a hilt--no blade at all. Suzuki explains that the Sword of Trials is a leech; it draws on the user's energy to create a blade which suits the user's personality. When Shishiwakamaru owned it, it became the Wailing Vorpal Sword.
Let's not speculate about what this means for Shishiwakamaru's spiritual hygiene.
Okay, let's. The Wailing Vorpal Sword emits screams which make your ears bleed, belches forth skulls which eat everything they see, and sucks the strength right out of your body. If this is a reflection of Shishiwakamaru's soul, then that pretty face hides a spirit even darker than the usual run of evil bishonen.
Or if you're of a less reverent nature, then the Makokumeizanken is a diva sword. How fitting.
How... Freudian.
I wonder how Waka-sama feels now that his favorite toy has been given to Kuwabara.
That's terribly Freudian, too. Let's not explore this theme any farther, shall we?Makokumeizanken: The Wailing Vorpal Sword.
Onkoshoubakuheki: By thrusting the Wailing Vorpal Sword into the ground, Shishiwakamaru can create a wall of rushing ki. He uses it to keep his speedier opponents in place while he takes the Wailing Vorpal Sword to them.