Kit = skill set.
Viable means they are still playable in the meta. Galio is still a good mid just not as strong as he used to be when double AP was very popular like a year and a half ago (aka fell out of favor) basically there are better options than him now. Nonviable mostly means that their skill set is so odd or outdated they will have a hard time no matter what. Take Sion for example his skill set makes zero sense whatsoever. That's why he is getting a rework. Other examples are karma, heimerdinger, and warwick. inb4 "those said champions are good!" no they aren't thats why riot is reworking them.
You can play galio support, but don't expect it to ever out perform any of the standard supports that can do what he does but way better. Heck i used to play ashe and caitlyn support awhile back lol. If your playing 5's and they don't mind you playing unconventional supports then go for it, but in solo que you'll probably end up getting banned for playing against the meta. I learned this after i got a suspension for playing roam annie like 5 games in a row.
Viable means they are still playable in the meta. Galio is still a good mid just not as strong as he used to be when double AP was very popular like a year and a half ago (aka fell out of favor) basically there are better options than him now. Nonviable mostly means that their skill set is so odd or outdated they will have a hard time no matter what. Take Sion for example his skill set makes zero sense whatsoever. That's why he is getting a rework. Other examples are karma, heimerdinger, and warwick. inb4 "those said champions are good!" no they aren't thats why riot is reworking them.
You can play galio support, but don't expect it to ever out perform any of the standard supports that can do what he does but way better. Heck i used to play ashe and caitlyn support awhile back lol. If your playing 5's and they don't mind you playing unconventional supports then go for it, but in solo que you'll probably end up getting banned for playing against the meta. I learned this after i got a suspension for playing roam annie like 5 games in a row.