This build is focused on fighting isolated targets, catching out the enemy top laner, jungler and mid laner is a pretty guaranteed kill, whether if you're tanky, your only CC can just be removed. The only way to counter this build forces the enemy team to waste a lot of gold, getting qsses on all solo laners/jungler, if an enemy qsses your ult, you have still closed the gap, once red buff is applied, they are not going to get away and diving turrets is easy because of the amount of health your Q gives you.

Trundle, Galio, Alistar, Mundo, Sion, Garen, Leona.

Why?

Trundle will cast his ult, allowing him to survive your ult, then he will steal your damage and resistances and beat you.

Galio will cast Bulwark, and because you're attack speed based, he's going to heal for a lot of the damage you deal, and most probably still get away with his righteous gust.

Alistar has an inbuilt QSS, after ulting your ult he will pulverize you and headbutt you into a group of people, which is the last thing you want.

Mundo will activate ult before you ult or even after since he will have stupid amounts of health by late game.

Garen similar in terms of health to Mundo and his Courage ability.

Sion will have a shield which doesn't have any resistances to drop so your drop becomes a little useless, he will then just ult away and you'd have wasted your time.

Leona will activate w or even ult before you ult, negating almost all the damage and she will then just stun you and walk away.

You have hybrid damage, your enemies will have 2 resistances to build for, MR will be shredded anyway.

You're dealing 5 on-hit attacks with your ultimate, if you have 5 auto attacks on your target before you ult, your passive will deal 48 magic damage per hit, your devourer will deal 50 damage per hit, your blade of the ruined king will deal 8% of an enemy's health per hit, your nashor's will deal 15+15% of your AP, Wit's End will deal 42 magic damage per hit, your ult by itself will do 70+0.4 of your bonus AD all in magic damage. Your Wit's End will have all benefits and rageblade will have all benefits on the last 2 on-hit effects of your ultimate.

if you add all that damage together, you can easily kill any adc or apc out of position with ult and for any off-tanks/bruisers you can finish them with Q.