I provide a bit of an explanation to my reasoning behind this suggestion, but it's not necessarily required if you only care about the basic idea and not why I think it would be a good thing. If you want to skip the explanation, just jump down to the bolded "Idea" tag.
So... while I think a few of the early heroes could use a bit of a "going over" to make them more relevant in this age of massive power creep in the game, that applies to none moreso than Paladin.
I can't speak for everyone, but I know for me and most of the people in the guilds I'm in he was a placeholder at the very best (first hero replaced for almost everyone I spoke to). Now he just sits there in my Altar, never being used, but kept for the might boost.
When the Bios came out, I hoped we might see Paladin get a tune up to at least try to make him useful again, since Paladin's Bio is directly tied to another, far more useful, hero: Valentina . That never happened though, nor did I really expect it to.
So my suggestion is to give Paladin a special bonus any time he's running alongside Valentina, since his Bio denotes him as her "personal bodyguard". When she's around, he becomes a more zealous defender, making him or possibly the whole team a better defender.
The idea comes in two "flavors".
The first is that Paladin personally guards Valentina, when she's on the field. He stays near her, pulls aggro from her, and keeps her safe until he dies. He also personally becomes more useful during this, by getting a boost to his attack speed, attack damage, and possibly a weak life drain effect so that he is a better guardian for her. No matter where he is dropped he will go straight to Valentina, to do his duty.
The second follows the same general premise, with him taking agro and going straight to guarding Valentina above all else. But in this one the boost to speed, damage, and the life drain effect is applied to the whole team, the reasoning being that by helping the whole team, Valentina will be safer.
For the effect to come into play, both Paladin and Valentina have to be on the field and Paladin has to be in range of Valentina (he stays in range unless fighting, then immediately returns to her).
I kinda like both versions. I think the first is a bit more on point, while the second more useful overall. So it is hard for me to say one over the other.
Also, just to be clear, I'm not talking huge bonuses with those boosts. Maybe something on the level of a 30% increase to attack and attack speed, and maybe life drain 2 or 3 for the team version. A bit higher boosts for the Paladin only version, since he would be fighting harder without "help".
So that's my suggestion to make Paladin more useful.
Move along, please.