drop table if exists mega_table;

set @max_rel_return_id = -1;
set @counter = 0;
set @last_counter = 0;

create table mega_table (
  select
    @max_rel_return_id := IF(counter = @counter AND @counter > 0, @max_rel_return_id, 0) as "swap"
    , @counter := counter as "counter"
    , (select returns.reason from returns where returns.counter = @counter and id > @max_rel_return_id order by id asc limit 1) as "reason"
    , @max_rel_return_id := (select returns.id from returns where returns.counter = @counter and id > @max_rel_return_id order by id asc limit 1) as "return_id"
  from (
    select * from things order by counter asc, id asc
  ) as things_ordered
  order by things_ordered.counter desc
);

alter table mega_table drop column swap;

select * from mega_table;