I've played plank since season 2 and I've built on him everyway but mage plank. Trinity,Atmogs,GB IE crazy man, racecar (Shurelia's+GB+Trinity+ghost), bank plank(triple gp into GB,Omen,Shurelia's). Mallet, Black cleaver(-45 armor is op ****), partial support, full support, oft tank, full tank. You name it i've played it and I can't for the life of me get plank to work in season 3. Overall resists changes, cdr changes,and attackspeed changes put the nail in this pirates coffin. When you throw in things like the lack of indomitable(which kills early all-ins), the block mastery/doran's shield, and the general reduction in item premium value(plank is super item dependent). His jungle has been pretty awful for a long long time and his lane is plagued with some awful worst case match-ups( Riven, Jax, and Pantheon are essentially hard counters).
He's survived up until now despite all the nerfs(he was op with 5 stacks and even probably with 4), the insult to injury nerfs like his q mana cost and loss of range on raise moral put him over the edge.(it basically forced philo stone every game) He recovered when they gave his q the mana refund on minion kills.(did nothing for his jungle though which is still plagued with mana issues) Plank's been through a lot but he's trash now and he really needs something. (you have no idea how sad I am to say that but I really have lost faith in the pirate.)
My messy posts needs TL;DR
I've been everywhere man.
Season 3 broke the pirate.(I ate oranges but it isn't k)
RIOT FIX IT!
Let us have the PIRATE.