When my PCs in my current second game were building their party, naturally the roles the first three party memebers (out of a party of five) were attracted to were all strikers. Conventiently a solution to the obvious problem herein presented itself when the player who wanted a Warlock stumbled upon the section detailing the Binder sub-class in the copy of PoHoS that I am carry to games. I deliberately avoided mentioning that this class is reasonably regarded by the community as drastically underpowered because I didn't want to discourage him latching onto the RP part of his character because A: I needed to avoid another Striker in the group; B: I can always alter or add stuff later to bring this build to balance, as I am confident I have found most of the solution in this additional future.
After completing less-than-exhausting research (lazily flipping through books and adding up bull crap numbers) I have found what I am confident will make the Tiefling Binder in one of my groups bring as much to the table as any other controller and give him a flavor all his own, all while enabling him to draw feats from prior content and have his character fit inside of the very attractive lore fluff that was presented in the disapointing afforementioned book recently released.
The following feature I propose added to the features listed under the Binder's level 1 features, replacing nothing. Absolutely no one will disagree with the notion of adding a fifth feature to balance out this class. It is simply down one feature from the other 'lock builds.
A Binder learns to harness the fell energy surrounding her targets so that she can redirect this magical energy into the spells she uses against her hapless enemies, sustaining negative effects she places on them while aiding her allies in applying their own devious tactics to the very same target. You have this feature in place of the Warlock's Curse feature used as described in the Player's Handbook, but you still meet the prerequiste of Warlock's Curse for the purposes of aquiring feats and paragon paths.
Once per turn as a minor action, you can place a Binder's Bane on the enemy nearest to you that you can see. A bane-inflicted enemy is more likely to remain hindered or punished by you and your allies' attacks. Each enemy afflicted by a Binder's Bane takes a -2 penalty to all saving throws. In addition, once per turn as a minor action you can designate a creature you can see that you have applied a bane to. If you do so, you can change a single effect on that creature so that if it the effect would fade at the end of your turn, that effect now fades if the creature succeeds in a saving throw at the end of your turn. Otherwise, the effect persists until the end of your next turn instead and you are free to attempt the effect again during that and any other subsequent turns.
A Binder's Bane remains in effect until the end of the encounter or until the bane-inflicted enemy drops to 0 hitpoints or fewer.
You can place a Binder's Bane on multiple targets over the course of an encounter; each bane requires the use of a minor action. You can’t place a Binder's Bane on a creature that is already affected by your or another character’s Warlock’s Curse or Binder's Bane.
Obviously there are several snags with this, but above all else I am fully confident this is not overpowered at all when looking through the Binder powers available in PoHoS. As far as whether there is something more devious available in other materials, I would love to hear about it from the board.