So you feel that an item which is completely overloaded with stats is the answer?
Just did the calculations, a level 6 Talon with MR glyphs and a Hexdrinker gains 725 additional effective HP vs magic damage. That's not including any +max HP they may have somewhere else. This brings a level 6 Talon to an effective HP of... 1985. (84 MR with 919 HP + 160 shield)
If brand lands literally everything including a perfect ult, he will deal 656 + 240% AP damage. Thats if he gets the bonus damage on his W. When his passive procs, he will deal 133 + 14% AP damage. So the total max possible damage is 789 + 254% AP. Add his passive burn (let's give it 6 seconds) another 8% of his max hp, 73 damage. So 862 + 254% AP is our raw damage. That means, to burst through a Talon who has nothing but a Hexdrinker, he would need 442 AP. And that is landing an absolute perfect combo with every other bounce of Brands ult hitting him. It takes 442 AP for him to burst through that 1300g item that ALSO gives him 700g of AD. That is 9613g worth of AP that he needs just to burst through your one item which is 600g for the non-AD stats.
Let's see Talon's combo on a RoA+Rylai's Brand. Let's say both are level 13? And assume somehow magically the RoA is fully stacked. Hell let's give brand a Doran's since he would likely have that too. Brands effective HP would be 3887, but consider Black Cleaver's armor shred. Let's say his armor is reduced by 15% on average (half of a fully stacked cleaver). That brings his HP to 3634. Talon's skills and ratios at level 13 come out to be 800 + 200% AD + 400% bonus AD for a simple EQWR combo with no additional autoattacks. And that is amplified by 3% from his E. His passive also gives 10% bonus damage since they are slowed by the passive, but that doesn't apply to the initial autoattack that is done immediately after E. Let's also split the base AD and bonus AD. So that comes out to be 904 + 226% base AD + 678% bonus AD. His base AD at level 13 is 89, so that's 1104 + 678% bonus AD. He would need 410 bonus AD to 1 shot the Brand at that level. Of course that is reduced by a LOT if you just autoattack one more time, bringing that down to 338 bonus AD.
But that's just raw AD, and Brand has like 6k in items. Let's say Talon also only has two items, Youmou's and Duskblade. That's 30 Armor Pen and 140 AD, and 15 more AD from runes.. Brand's effective HP would be 3197. With a single autoattack after the main combo, the damage becomes (904 + 339% base AD + 791% bonus AD)x(1.25)+90 = 1220 + 424% base AD + 989% bonus AD. Again 89 base AD means 1597 + 989% bonus AD. 155 bonus AD = 1597+1533 = 3130 damage. 67 raw damage short of a dead Brand. So for 6400ish gold you can burst through his 6200g which also is assuming he already has 10 minutes of stacks on RoA. But Brand needs 9k gold worth of AP to burst through your 1300g at level 6.
BALANCED.
Edit: I forgot to add the 13% damage from his passive and E onto the 25% missing hp proc from Duskblade, meaning it would be x(1.285) instead of 1.25, meaning the actual damage output is actually slightly higher.
Edit 2: Since you are going to say the situations are unfair, let's do a level 13 Talon with Maw. Just Maw and his flat MR glyphs. He will have an effective HP of 3676 vs magic damage (1514 base HP + 352 from Maw)x(1.97 for 97 MR). Brand's max damage will be 1189 + 240% AP before his passive, which will be 121 damage on the burn, 242 + 23% AP. Totaling to 1552 + 263% AP. Brand needs 807 AP to burst through a level 13 Talon with just a Maw. 17552g worth of AP. More realistically though, Brand will have Sorc Shoes and 8 Mpen runes, dropping Talon's effective HP to 3246. He still would need 644 AP (14,000g worth of AP) to burst through Maw (3250 gold)
Hexdrinker and Maw are obscenely broken items.