Biggest wall in each game?

Not necessarily the hardest boss, just the one that felt like the biggest obstacle to progressing the game, the most seemingly overwhelming/unwinnable/laborious fight.
For me it was Bell Gargoyles, Ruin Sentinels, Maliketh, Vicar Amelia, and Guardian Ape. Dark Souls 3 never had a wall, I beat most bosses pretty quickly.