Chaos being struck by Thunder Arrow
A lightning bolt that damages and disorientates the opponent
Thunder Arrow is one of Knuckles the Echidna's special moves in Sonic Adventure 2 and Sonic Adventure 2: Battle. Unlike most of Knuckles' other techniques, he can only perform this move when he is played in the game's two-player mode and has gathered enough rings (He also uses it during his battle with Rouge the Bat on board the Space Colony ARK, but only as a boss in the Dark story). It is a lightning bolt that Knuckles strikes his opponent with.
In Sonic Adventure 2's gameplay, Knuckles can only use the Thunder Arrow technique when he is played in the game's two-player mode, where two players races each other in a hunt to collect most of the Master Emerald's Emerald Shards.
To perform Thunder Arrow, Knuckles has to collect at least 40 rings. As soon as he has done that, he can use Thunder Arrow unrestrained. When using this move, Knuckles shouts "Take this" and will form several lightning bolts above the opponent and strike them with them. This does not only causes damage to the target, but also makes the target disorientated. This move is hard for the foe to escape, but you can Dig or Glide quickly to avoid it.
The Thunder Arrow move has also appeared several times in the Archie Comics. In this media, the Thunder Arrow is a bolt of Chaos Energy, similar in appearance to the Chaos Spear, but the user rather summons them in bursts of energy than throwing them as spears. It is commonly used by characters that have a strong connection to the Chaos Force, such as Knuckles the Echidna, Enerjak and Edmund, and acts as a Chaos-powered, arrow shaped lighting bolt that electrocutes its victims.
During the battle between Super Sonic and Knuckles in his Enerjak persona, Knuckles tried to defeat Super Sonic by hitting him with Thunder Arrow, but could not harm him because Super Sonic was invincible. He later used this technique again, against Dr. Finetivus in a battle with Chaos Energy on Angel Island. The future guardian Edmund from Silver the Hedgehog time line also demonstrated the use of Thunder Arrow when he attacked Prelate-V.