Rammus + Ethereal Weapon

Build around the Upgrade: Thornmail hex. Use W's huge resists with Heartsteel and Warmog's for HP, then stack magic pen via Void Staff, Abyssal Mask, and forge. Once enemy MR is fully penetrated, Thornmail damage becomes near-true. Forge: magic pen > resists > HP. W also benefits from Jak'sho's % resist scaling. If enemies refuse to attack you, taunt with E to force the reflect.

Protein Shake Rammus — full tank, AS easily hits 5.0. Protein Shake fits perfectly with W.

Rammus W perfectly procs Ethereal Weapon; W also procs Gash. Core items: Heartsteel, Thornmail, Sterak's. When attacked, you trigger W damage + Thornmail damage + Gash damage + Heartsteel stacks and damage.

Chili Oil for sustain — W instantly procs Chili Oil, stand and heal; if low, Q to back and heal during reset. Items: Bramble Vest first, then Sunfire; with extra AP go Radiant Echoes; third item Abyssal Mask; rest is tank stuff for the lineup. Easy early lead.