Nerf Master Yi late game, or remove armor pene from regular items.

ALL items with armor pene should be nerfed. They are just too useful. OK they are expensive, but damage dealers have no problems with gettin money. Look items like these are just must-be-item for any bruiser/melee adc 300 hp, 50 ad, 20% cdr, and armor pene... perfect stats. Penetration up to 30% 65 ad, 10 cdr, MS, AS buff, Penetration 20 55 ad, 40 mr, shield 300+mr value, buff to lifesteal/spellvamp when low hp (previous guinsoo buff). Penetration 10 Last whisper - pene 45% bonus dmg +15%

I understand this kit is for adc, that is squishy and only thing he can do is few hits with AA before assasin will kill him.

Problems happen when AD Bruisers or melee ADC building bruiser like Bruiser Yi, or Bruiser Fiora that are stupidly op have those items. It has no matter you have up to 250 armor. Armor pene is so broken, that Yi is eating you with 3-4 hits, while he has 2,0 AS it means 2 hits per second. + flat pene from runes and masteries = he deals dmg close to true dmg.

Penetration should be removed from these items. There should be only Last Whisper to force AD dealers to build it. It should be counter for heavy armored champions. In this moment, ad dealers dont need to build it, coz flatpene and % pene from bc is so high, that they dont need anythin else. Lets calculate Malmotrius = 10 + tankyness (shield,mr,life steal) + huge ad bonus BC = up to 30% + 300 hp + huge ad bonus + 20% cdr srsly? Srsly riot? So many things in one not so expensive item. Youumu = 20 pene + 65 ad + 10% cdr + lowcd buff for MS/AS srsly? Srsly riot?...

So Bruiser Yi build: Runes: Armor pene 11.5 Health 72 Magic resist 27 AS 13,5%

Masteries: 7%armor pene 10 ad 4%AS +14 dmg per hit up to +102 per hit

35% as 50% as + 4% magic dmg of enemys hp 55 ad, 40 mr, 480 shield, 10% lifesteal, 10 armor pene 300 hp, 50 ad, 20% cdr, up to 30% armor pene 20 armor pene, 65 ad, 10% cdr, 40% as now if Yi builds Dominics bow he have 45% armor pene + 15% dmg to heavier champs.

so regular offtank (i wont even mention turbosquishy carry) 250 armor 2700 hp 250 -45% = 137,5 armor

• 41,5 flat armor pene = 96
• up to 30% per hit (-41,25) = ~~55 armor According to wiki damage reduction 25 armor → ×0.8 incoming physical damage (20% reduction, +25% effective health). 100 armor → ×0.5 incoming physical damage (50% reduction, +100% effective health). −25 armor → ×1.20 incoming physical damage (20% increase, −16.67% effective health). We have 35% dmg reduction. Now calculate dmg output. 60 + 3*18=114 base ad +55+50+65+10 = 294 AD 294 - 35% = 191,1 true dmg after armor reduction.

• 50+20%ad =301,1 +15% from dominic bow = 346 +4% enemy hp = 454 454 true dmg per hit. You think darius ult is sick? pff We have 40+50+35+4+13+36+80% increased attack speed from 0,679 =246,444 = 2,5 AS it mean 5 attacks in 2 seconds. + one attack every 4 hits that deal half dmg = 5,5 attack in 2 seconds * 454 true dmg= 2497 dmg in 2 seconds he is able to eat 2500 hp + alfa strike = death. You are not even able to make him CC in such time. If he flank you and start from squishis its like alfastrike+1 hit to kill. This is even more toxic than his AP version. And we are not exaclty glass cannon. We have 2256 base hp + 300 bc + 480 shield. I wont even mention his Alpha strike that protects him from any kind of burst or focus.