Legendary characters as a rule of thumb generally are pretty broken, but the bit that sucks more is the lack of versatility in classes. There is some wiggle room, but typically every class is shoehorned into one or two types of builds which are purely eq based. Theres minimal customisation. I mean, sure you can stack dodge on a thief as opposed to stacking damage, but fundamentally the playstyle doesn't change.
What could be cool to unbapt legend a bit and add some variance would be to break up legend a bit into specific "capstones", each with their own shtick. You could reuse coded content from other classes, so there wouldn't be a huge amount of work. Capstone should be things which are useful for the class, not horribly game breaking, but offer a new dynamic. This would allow customisation while also repealling some of the brokenness of legend by limiting how many legend ranks you can get - as you could only have one capstone at a time. Further, it would open up a ton of unorth
If you're wondering what the bapt im talking about, here's some hypothetical examples:
Thief
All legends - Access to legend pick rank, adrenaline rush and retaliation
Shadowblade capstone
Access to legend backstab rank
"Gloom" keyword - casts darkness - 4 tick recharge
Assassin capstone
Access to legend envenom rank
Gets the bash skill (auto superb) - use has 2 tick recharge
Distortionist capstone
Gets legend dodge rank
Gets "shimmer" keyword - casts mirror image - 3 tick CD
Gets "relocate" keyword - casts blink - 20 tick cooldown
White Robe
Baseline - gets boon and wither spells, gets access to globe rank
Purifier
Gets access to the cleanse rank
Gets heal as a 9th slot spell
Arcane warrior
-100% spell damage
Extra attack flag
3 damroll, 3 hitroll, +10 shortblades, +10 bludgeons, +10 miscs
--Couldn't think of another off the top of my head--
Cleric
Baseline - ameleorate, rapture, access to legend heal
Warpriest
Gets the strike skill
Gets access to legend steelskin
Danse Macabre
Accesss to animate dead rank
Gets flesh shield spell
Gets zombify spell
Anyway, you get my point. Indirectly a change like this would actually be a nerf as a result of only being able to get 1-2 legend ranks, but it would provide a greater level of customisation than we've seen (If there's 3 options per class).
Just an idea.