In Dota there are many items that change the appearance of the hero very much, making him better, changing icons and animations of his abilities. The best of these are Immortal items, because they contribute the most to the appearance of the character. 
They cost differently, but their purchase will give the owner a lot of positive emotions, because sometimes your favorite hero completely changes his appearance. I propose to consider the best of them in our subjective opinion.

Focal Resonance 

Legendary hands on Templar Asassin. Very much change the appearance of the hero. Change the animation of the third ability and also make the icon golden. Their main thing is that they are universal, and combined with many sets in the game. Cost about 7 dollars, and are the best buy on this hero.

Blade of teers

A set on Morpling that consists of a head and arms. There are few good sets on morpling, but due to this they are not required. The skins change the icons of all abilities except ultimates, as well as the wave view, and the adaptive view. In a complete set, the set costs about 30 dollars.

Arms of Desolation

Everyone knows the Arms of Desolation on sf, which changes the animation of his attack, and its color. A must-have item for every SF player. Combine well with Arcana, and look great in a set. Cost about 5 dollars.

Golden Mandate

Golden legendary shoulder pad on Storm Spirit. A really nice piece that changes your passive ability animation, attack color, and main icon. Plus it just looks good, since it's presented in the form of a shoulder pad that everyone has in front of their eyes. It costs around $15, but you can find her more budget-friendly blue version that costs $1.5.

Codicil of the veiled Ones 

As far as I'm concerned, this is the best immortal item. Presented in the form of a mask, and it looks just great. Its main draw is that this item combines perfectly with the harness, and it looks like they are one in the same. It costs $15, which is not a small amount, but is a must buy if you are a fan of this character.