@Kurohige: What exactly can Pride do?
@SpeedForceSpider: Create shadows that can eat you, his only weakness is lack of light (Can't amke shadows) with the shadows it is really hard to kill him. Aside from the Homunculi's standard powers, Pride's abilities lie within his shadow, which resembles the original flask-contained form of Father although much larger and more formidable with multiple slitted eyes and sharp toothed mouths. The shadow can take on a variety of shapes, from sharp spikes to tendril-like hands (similar to those seen within the Gate of Truth). Pride can manipulate, slice through or devour anything that comes in contact with his shadow and it appears invulnerable to conventional physical harm, although it can be deflected by sufficiently hard objects; Carbon-hardened objects appear particularly resistant. He can also see and talk through his shadowy eyes and mouths wherever his shadow can extend, an ability he uses to watch over the country-wide transmutation tunnel, this is supported by the shadows limited mobility, only being able to appear in the immediate surroundings of his human body and in the circular transmutation tunnel around Amestris. It also cannot appear without a light a source and can be harmed when light becomes too bright.
Pride's shadow can consume living things and assimilate the abilities and strengths of that particular victim, along with their corresponding weaknesses (i.e. after devouring Gluttony, Pride gained an enhanced sense of smell along with Gluttony's ravenous hunger). After assimilating the Gold-Toothed Doctor, Pride gains knowledge of human transmutation and activates a corresponding circle with his shadows.
Here are some videos of him
@SpeedForceSpider: No since Stands can only be seen by other Stand users plus it's a spritual manifestation of the user,it can also only be hurt or destroyed by other Stands, Pride can't really defend against it, I'm sure he can regen from Emerald splash, I'm not sure how the body take over would work, but not being able to see the Stand gives kakyoin an advantage, I think it depends on if Kakyoin can keep Pride at bay until the sun goes down. Hierophant Green should also be much faster than Pride. It's a matter of Kakyoin holding out since his stand is not physically strong and he will have to focus on getting himself out of there as Pride has tons of lives and will eventually sneak a shadow behind kakyoin, I think kakyoin can take this if he can get away and creat his kekkai barrier like he did against Dio, using a Stand requires no energy no he can spam emerald splash all he wants but I think Pride's shadows are durable to take it (Since he will likely put up a defense after the first few deaths lol.) But if Kakyoin get's the barrier Pride can't do a lot, I think it can go either way.
@Kurohige: Well actually Kakyoin is a pretty smart dude so it is highly probable he would figure out how to beat Pride. All he has to do is hide out and keep his distance and let Hierophant Green loose. Remember his membranes can uncoil and trap people while sending electrical waves through them so Kakyoin can do that and spam him to hell with Emerald Splash. If it doesn't finish him it can be a distraction while HG moves in to posses his body and its pretty much game over. And yeah as you have said HG moves at Relativistic speeds and from what I have seen with Pride in combat he is not all that quick.