Shinsu Resistance is an ability that allows one to resist a certain density or viscosity of Shinsu. Because Shinsu can be many things in the Tower, Shinsu resistance could even be defined as an ability to withstand a certain amount of almost anything or possibly, everything made up of Shinsu.
All Tower inhabitants such as Shinheuh, humans, and other species have varying amounts of Shinsu resistance but there are also some individuals who have side-effects to high concentrations of Shinsu. If the density is much higher than one can withstand, it can cause pain, nausea, bleeding or even death to an individual. Based on the amount of Shinsu resistance one possesses, one might survive a certain amount of damage incurred from Shinsu attacks caused by ability or an item.
Depending on one's ability, this means one can even enter and move around in areas with a certain amount of Shinsu density without incurring too much, if any, restriction of movement. One can also try to force themselves through a barrier with a density somewhat higher than their body can withstand but they might suffer some injuries, like bleeding.
All known Irregulars who have developed much of their abilities, are likely to possess very high Shinsu resistance and Shinsu manipulation.
Observable Properties of Shinsu Resistance
There are a few instances in the series where some of the properties of Shinsu resistance can be observed. Shinsu will cause friction with objects moving through it. The less Shinsu resistance one has, the more friction is applied to oneself. This was heavily implied in the first chapters when Baam faced the White Steel Eel and negligible "friction" was exerted on Baam, demonstrating his high Shinsu resistance. Later during the barrier test administered by Lero-Ro, the friction against the Regulars was strong enough to push them back. Also, Kurudan commented that normal people would have a great force exerted on them while going into a Steel Eel dwelling, since very few Regulars have the Shinsu resistance of an Irregular. Apparently high Shinsu density areas require high Shinsu resistance in order to successfully navigate through them. Extreme Shinsu density can even mangle a person. According to Lero-Ro, having low Shinsu resistance should be compared to being allergic to Shinsu. Another good example is when Khun is passing through the Shinsu barrier, he himself has no issues whatsoever but Manbarondenna, which carried additional Regulars with lower resistance than his, had a lot of friction being exerted on it.
Also, it seems Shinsu resistance can be a hereditary trait upon the Tower's inhabitants, especially those from the 10 Great Families. For instance, Yuri Zahard has unnaturally high Shinsu resistance, so she experiences barely any restriction of body movement. She probably inherited part or all of this resistance from her great-grandparents Ha Yurin.
Boosting Shinsu Resistance
There are also ways Shinsu resistance can be increased by natural or artificial means.
- By adjusting to an area of high Shinsu density like Rak Wraithraiser who likely hunted on Shinheuh in areas of different density.
- Through items like the Mule Glove, which is an Armour Inventory capable of increasing Shinsu resistance.
Note: There may be even more ways of increasing Shinsu resistance and it's also unknown if one's natural Shinsu resistance can stop developing.