This is exactly what i said :
But like i said it’s too dangerous to go up-there… the only problem is that the sentry doesn’t always shoot at you when you are on theses wall
All character who can reach thoses walls : Attikus, Benedict, Caldarius, Deande, ISIC, Kleese, Mellka, Phoebe, Whiskey and Thorn
All the character who can counter them when there is someone up there : Alani, Attikus, Benedict, Caldarius, Deande, Galilea, Ghalt, ISIC, Kleese, Marquis, Mellka, Miko, Montana, Orendi, Oscar, Phoebe, Reyna, Shayne, Thorn, Toby, Whiskey
Only Ambra, Boldur, El Dragon, Kelvin and Rath can’t really counter them (you can still hit them)
So there is no problem (except the sentry bug)