Well I guess hero should call. Re-raising here is really trying to target a pretty specific range, namely the aces up combos AQ, AT, and maybe the case A5s. I don't think villain ever shows up with QT (unless this TAG is closer to LAG with steal raising) or any other two pair combos. Villain can show up with TT, AA, unless hero can rule those out based on the turn action, KJ is a possibility here too. Villain c-bet, called the raise, got free card on the turn because hero checked and got there. QQ is a similar story.
A reraise on the river kind of sorts villain into only his stronger range and 55 really is in the middle of that, and hero is sure to get reraised by the best of that range, and hero is also granting villain the chance to fold the one pair Ax hands by raising.
So congratulations on basically turning a strong flop into a bluff catcher? I guess hero gets three bets of value this way, but two of them were for small amounts on the flop. Hero could have gotten four bets, the last two being for bigger amounts while forcing villain to bluff catch with what figures to be most of his range, the Ax one pair combos. If villain has it, then I guess this line saved hero money this time, but hero is probably missing value in the long run by playing turn and river so carefully/deceptively.
If hero raised the river and got paid by aces up, that's the best case scenario in how I see this hand ending. But that has to compensate from the amounts villain would call a simple lead on turn and river with Ax, and the amounts lost when villain 3 bets better sets and straights.
calls.
