Thundercloud

History:

While Bowser had years ago harnessed the power of the Thunderbolt to work contrary to the Star, it was only recently that he developed a more personal variation of the Magic Lightning. As the Purity of Star Power, or even Mushroom Technology, continually eluded his grasps, he again attempted to use his knowledge of Dark Magic to work through alternative speed boosts. He struggled mightily to come up with a means to use Lightning Power to achieve the same ends. Using Lakitu Cloud Technology, he isolated the Thunderbolt to only strike a single player at a time, which at small doses, would charge them with incredible force and speed. Prolonged exposure, however, led to a similar effect as the course-wide Thunderbolt calamity, except isolated to one driver. Bowser, ever the gambler and delighted that his new weapon could be used defensively and offensively, decided to go ahead and submit his imperfect technology, although it was only accepted to a single Grand Prix.

The Thundercloud appears in:

Wii

The Thundercloud is an intriguing item because of its aforementioned defensive and offensive nature. Once activated, the personal storm cloud boosts the user with Lightning, which provides a sustained speed nearly equivalent to a Mushroom Boost and negates Offroad Conditions. Once the Lightning runs out, however, the user is struck similar to a Thunderbolt effect, except he or she is the only shrunken player. The catch is, that at any time the Thundercloud may be transferred to another racer through physical kart-to-kart contact. If your timing is correct, this means that you can get all the benefits of a speed boost, and then ram into someone and pass off the ill effects. However, this means that the Thundercloud virtually cannot be used to get into First Place, because when there is no longer anyone around, you will shrink, wither, and fall behind.

There are other plays to be made, however. It is risky, but if there is a crowded pack of racers you may attempt to grab the Cloud from someone else, boost forward, and then keep passing it. This is dangerous, though, if you do not know how long the first person has had the Cloud activated. Another decent strategy if you get ahead is to actually slow down in a narrow stretch and try to let someone from behind run into you. This will give them an advantage momentarily, but when they shrink you can surge ahead.

Like Mushrooms, while the Thundercloud grants a boost, it does not grant Immortality like Stars do. This means that while speed is increased, the potential for hazards also increases. Thunderclouds are negated by Stars, Mega Mushrooms, and Bullet Bills. In general this an Item to avoid because of the high amount of advanced strategy required to effectively deploy, as well as the risk that often is higher than the reward, especially when compared to other Speed-granting Items. Any good effect is essentially negated by the time it runs out if there are no other drivers nearby. It requires timing more complex than perhaps any other Mario Kart Item.

Thunderbolt

History:

It was Bowser's Dark Magic that first harnessed the power of Lightning. Lying under the constantly stormy skies of the Dark Land, Bowser was able to capture the daggers from the sky and confine it to an Item Box. Known more often as the Thunderbolt, this item was seen as counter to the Benefits of the Star. It would destroy all other players and allow its user to race ahead.

The Thunderbolt appears in:

64
Super Circuit
Double Dash
DS
Wii
7

The use of the Thunderbolt is similar in every game. Usually players have to be pretty far bac64 and Super Circuit, where the effects lasted longer and players were squished if run over (this returned in 7). From Double Dash on, Players are merely knocked around more easily, and from DS on players in a lower place would be affected for a shorter period of time.
k to get it from an Item Box. Once activated, every other player on the course is struck by Lightning and shrinks down to a miniature size. This makes them much slower, as well as more vulnerable to hazards on the course, including other racers. It was arguably a more fearsome weapon in

The only thing that can counter Thunderbolts are Stars, or in later games, Bullet Bills. If a Racer in Wii is using a Mega Mushroom, he or she will be reduced to normal size. Mistimed Lightning is perhaps the most dangerous - if it strikes when going over a jump players will be punished into the Abyss. The only exception for many years was barrel cannons or other jumps that prevented the ill effects. When these kinds of jumps became conduits for Air Travel in 7 this protection was negated. This makes 7 a much more dangerous game, and indeed, with the squishing effect back in force, the Thunderbolt has some teeth again.

There's no telling when Lightning will strike. It's the number one reason not to hold on to items very long and is a great interrupter of strategy. From DS on, the Thunderbolt can cause players struck to lose their items, which was absent from 64 and Super Circuit. Generally this seems to happen whenever you've been holding a Red Shell for just the perfect moment to strike. It promotes a healthy turnover in gameplay.