Well let's first begin to break down the hand on the river. Although we should at the pre, flop and turn narrow its range down. He is preflop pretty wide, calling the blind and limping with approximately 50% of hands, could be a lot higher or lower but 20 hands out of 40 is pretty much, so he is more likely to be a passive fish.
On the flop he can have all the aces, kings, 2's and gutters and flushdraws. I don't know but he might even play all the suited hands, like 23s, 45s, etc. So he can call with a lot worse. No question about the big c-bet here, its pretty good as my opinion is.
On the turn there rolls of an 8. Since he is probably more like a calling station he could have all the pairs on the turn still. So it might improve him. But all the backdoor flushdraws, backdoor straightdraws might fold on the turn. A passive fish is more likely to give up his floats on the turn ip so he doesnt have a lot of random crap on the river. But I have seen such guys call down at least 2 streets with hands like a deuce.
On the river. Hmmmm you bet pretty big and leave yourself pot-committed. If we guess his range is still that wide with a lot of 2pairs, trips and his nutts. We get according to equilab the following range.
http://www.power-equilab.com
Board: 2hAdKd8s3s
Equity Win Tie
MP2 40.82% 36.73% 4.08% { AhKh }
MP3 59.18% 55.10% 4.08% { KK+, 88, 33-22, AKs, A8s, A3s-A2s, 54s, AKo, A8o, A3o-A2o, 54o }
Since he is passive preflop and we dont have read that he is passive postflop, lets assume he is passive postflop. He calls on flop and turn. So he has something, it might be a gutter or a worse 2 pair or a set. I assume he doesnt bluff but can value raise a worse hand.
So all in all. You dont have 2 to 1 on a call i believe. You need to call 4,53 for a total pot of 15,62. So you need approximately A / (A+B) = 4,53 / (4,53+15,62) = 22%
So all in all i think you are with top two pretty pot committed here.