I would NOT recommend TDD.
If you want optimal choice take War cry. You don't need really upgrade for it (so it's cheaper), you can take +20% damage passive vs taunted and with countestrike + warcry you can maintain it pretty much all the time on everybody (boosting damage, your guard and having more chances for payback strike to stun targets).
TDD is clunky. Low range, clunky projectile which love to hit someone else on way because boss moved. It's slow and there aren't really anything worth even on perilous which will survive enough for TDD to matter.
It's only useful on
a) bosses if you team can focus damage. If not, boss increased damage can even wipe you.
on revenants and arcane horrors in chest rooms
c) pride demons
Main problem are not bosses and those big mobs but groups of archers and other groups. TDD does not help you there at all. All you need there is taunt those mobs somehow (so your team can just focus on dps) and survive it (for which you got walking fortress if your guard is not enough). There is no time to aim with TDD and choose some big pride demon, brute or other higher health enemies in the group.