Kayle jungle /help

see this is my current Jungle kayle build and ive notice late game i do alot of extreme damadge but i feel a lack of magic pen and i was wondering if replacing any of these items while keeping my attackspeed at 2.50 and witouth removing alot of my damadge item what pen item or what item shud i add and remove so my build is more efficient my runes are 9 Armor 24.3 attackspeed -5cdr level 18, 12.1 magic resist basically i am having a tad bit problems against tanks against the squishys its easy but against the tank its a bit harder so id like help on what would add more of damadge witouth losing all of my attackspeed ty!