Terra Classic doesn't rely on outside oracles; it votes on its prices
Most blockchains buy price data from services like Chainlink. Terra Classic has its validators do the job themselves.
In each short voting round, validators submit exchange rates for terra-luna:native. The chain lines up all the answers and picks the middle one, with bigger validators counting for more. Validators who land close to it share in the oracle reward pool.
A vote too far from that median counts as a miss, and so does a skipped vote. Validators who miss too often in a set window lose part of their stake and get jailed, which drops them from the active set.
Per validator(.)info data, 86 of 87 active validators voted in the latest round.