Unfortunately betrayal feats has baked in it its own nerf right from the start
*“Teamwork” is a relative term. Many villains don’t concern themselves with collateral damage and make their plans with exceeding ruthlessness. Presented below are several teamwork feats with the common theme of reaping a benefit at your allies’ expense. All of these feats refer to an initiator and an abettor. The initiator is the one activating the feat (also referred to as “you”) and the abettor is an ally who also has the feat and whose presence and (perhaps unwilling) sacrifice allows the feat to take effect. Choosing one of these feats effectively grants consent for an ally with the same feat to harm you in combat, and vice versa, but evil characters are often willing to take big risks to get the upper hand. Some recruit devoted minions specifically to use in this way. Characters with class abilities granting allies access to teamwork feats (such as cavaliers or inquisitors) can select these teamwork feats normally, but allies who are granted these feats can use the feats only as initiators, not as abettors. An inquisitor could not grant an ally the Ally Shield feat and then use the ally as a shield, for example, but he could allow that ally to use him as a shield.*
I really wanted to play the inquisitor who thanks to cunning initiative and high dex and combat domain goes first and then gives callous casting feat to the Big Stupid Fighter and then acid splashes the BSF for 1d3 damage so he can get an immediate move and place himself next the target netting him a false pounce. Alas it doesn't work, maybe if you and your GM handwaves it...
Maybe an Eldritch guardian build...
You got his intent backwards there Wicky. He wants to BE the BSF.
"...Characters with class abilities granting allies access to teamwork feats (such as cavaliers or inquisitors) can select these teamwork feats normally, but allies who are granted these feats can use the feats only as initiators, not as abettors. An inquisitor could not grant an ally the Ally Shield feat and then use the ally as a shield, for example, but he could allow that ally to use him as a shield.*"
Edit: However, that does seem to be a rather clever use of that feat if you, yourself are the BSF >:DSo you can do this, a Cavalier could grant an ally the Saving Shield feat, allowing it to use the Cavalier as a shield but the Cavalier could not force the ally to act as his shield.
I actually used this exact concept earlier so I have a few insights :)
Will share them in the next post as I have time, I am kinda rushed atm :/
I get the impression the OP wants to have the ability to give allies their betrayal feats (like ally shield), so that their ally can use the OP's character as a shield. The line you quoted would allow for that.
That being said, pack rager (barbarian) and Holy Tactician (paladin) are the only other classes I found that grants your allies the feats whole sale. Normal inquisitors for example, only grant it as a sort of virtual feat to their allies. Allowing the inquisitor to use the teamwork feat for themselves only, even when allies don't have them.
Paladin is going to be questionable at best with zon as your patron and barbarians tend to be limited in terms of armor and you have to rage to grant the teamwork feats to your allies so I don't know how productive it's going to be.
Tactical leader is probably the route to go, along with fey foundling, In harm's way and the die hard line of feats. Then if you have room something like antagonize in order to get enemies to go after you in the first place.
Edit: You might consider taking a one level dip in unbreakable fighter to save on feats. Also, the human trait Heart of the Wilderness, synergizes well with die hard.
So my old character went with a Cavalier build with the Standard Bearer and Strategist archetypes and took the Practiced Tactician feat with Ally shield to do just that. I also gave him Saving Shield for a bit more Bodyguardness.
Additional options you could take might be the Combat Reflexes, Bodyguard, In Harms Way chain of feats as well. Even if you just stop at Bodyguard you can take the Helpful trait to grant +4 AC bonuses with your AoOs. Nothing to scoff at, especially when combined with Ally Shield above.
The Suicidal trait is also excelent for what you are hoping for. Fits thematically too.
Elsewise magic enhancements can be beneficial, the Benevolent enchant with Aid Anothers comes to mind.
Then there is the Ring of Tactical Precision in which you can imbue with a teamwork feat then give to someone. It does have a 1 person per ring limit tho, but anyone can do this trick!
As for something a little different, the Mobile Bulwark line of feats greatly improve your usage of a tower shield and Mobile Fortress even lets allies take advantage of the cover you provide. Its a different form of tank but it can still be very effective.
If you are willing to use 3pp then you may have some more options. Using the SoP ruleset gives you some usage of Teamwork feats with the War sphere, such as the Tactical Totem. Also check out the Squadron Commander feat and/or Squadron Elite drawback for some ideas of how to go about it a different way.
In a different vein, the Tactical Animation feat grants all your Animated Objects a teamwork feat.
Lastly, I built a different type of character that I might as well plug here :) He was a USummoner with the Twinned archetype. This archetype grants your Eidolon all your teamwork feats and makes for a great minion to freely abuse or even kill as he simply revives the next day. Perfect fodder for Betrayal feats >:D