''Gubrathian Fire? Well, you are correct, I can't state otherwise, but I don't see you using the spell in practical dueling. Of course, if you have devised a good tactic, the spell can be more than useful, but I do not think it would be the first spell on your mind when fighting someone that could harm you. But, as per the spell itself, it causes an object to burn forever. In the end, that means that the object on fire won't burn down, because it could then, not be on fire. It could also be phrased as a philosophical paradox, but take it as it comes and, if you're not 100% certain that you want your candle to burn forever, I would suggest not using it. Although, I could demonstrate it to you'', he said. He then took Angelique's quill and pointed his wand at it, casting the mentioned spell. ''And this is how it works in practice. I doubt you will have any need for it now, but if you want to keep it, collect it after class'', Wilson said.
He then turned to the Slytherin boy, whose name he did not know. ''It is interesting how you Slytherins only know of Dark Magic. Has Archer taught you that on her classes? Although, professor Delacour could have easily thought you the Storm Charm. It is very practical as an evasive spell, as the storm it creates could be used as a distraction. Tempestas!'', Wilson fired upwards, creating a small thunderstorm with a few drops of rain. ''And this is how it starts, and it can, if you have enough knowledge and experience, turn into a nasty thunderstorm in the end'', he said. ''As for the Thunderbolt Curse, it is a very rare example of extremely dangerous magic. Although it can be very useful, its usage is somethat restricted and avoided by many, even Death Eaters, as it is one of the spells that can easily fail and cause damage to the user. It is extremely complex and hard to learn and even hared to control, which is why you won't learn how to use it in school. If you ever cross paths with it... just jump, as far as you can. I shall now demonstrate to you its effects on a smaller scale, of course'', Wilson said.
He took his wand and conjured a dummy several meters away from him. He pointed the wand at it. ''Attonbitus'', he fired. Three small thunderballs came out of his wand and then hit the dummy, turning it into ashes. ''And that is the Thunderbolt Charm. As you can see, it usage on a smaller scale can be dangerous. I am, of course, able to use it to almost full extent, but you, and that is one of the most friendly advices you will get from me, should not use it at least 30 years from now, not because of the others, but because of you'', Wilson said. ''Now, anything else? Also, 15 points for Slytherin'', he said.