SQL> set serverout on;

SQL> CREATE TABLE persons ( person NUMBER (10));

Table created.

SQL>
SQL> INSERT INTO persons
  2  (SELECT rownum FROM dual CONNECT BY LEVEL <= 5);

5 rows created.

SQL>
SQL> SELECT * FROM persons;
    PERSON
----------
         1
         2
         3
         4
         5
SQL>
SQL> DECLARE
  2    v_shooter       NUMBER:= 1;
  3    v_killed        NUMBER;
  4    v_next_shooter  NUMBER;
  5  BEGIN
  6
  7    LOOP
  8      SELECT shot    , NextShooter
  9        INTO v_killed, v_next_shooter
 10      FROM (
 11        SELECT person,
 12               Shooter,
 13               Shot,
 14               Nvl(Lag(shot) over (ORDER BY shot),
 15                   Max(shot) over () )             NextShooter
 16          FROM (
 17            SELECT person,
 18                   Decode(person, v_shooter,'Yes','No')      shooter,
 19                   Nvl( Lag(person) over (ORDER BY person),
 20                        (SELECT Max(person) FROM persons))   Shot
 21                   FROM  persons)
 22      )
 23      WHERE Shooter = 'Yes';
 24
 25      IF (v_shooter != v_killed) THEN
 26          Dbms_Output.put_line('Now ' || v_shooter || ' kills ' || v_killed);
 27      ELSE
 28          Dbms_Output.put_line('Last Man Standing ' || v_killed);
 29          EXIT;
 30      END IF;
 31
 32      DELETE FROM persons WHERE person = v_killed;
 33
 34      v_shooter := v_next_shooter;
 35
 36    END LOOP;
 37
 38  END;
 39  /

Now 1 kills 5
Now 4 kills 3
Now 2 kills 1
Now 4 kills 2
Last Man Standing 4

PL/SQL procedure successfully completed.

SQL>
SQL>
SQL> DROP TABLE persons;

SQL> @lms
SQL> set serverout on;
SQL> DROP TABLE PERSONS;

Table dropped.

SQL> CREATE TABLE persons ( person NUMBER (10));

Table created.

SQL> INSERT INTO persons (SELECT rownum FROM dual CONNECT BY LEVEL <= 6);

6 rows created.

SQL> create or replace procedure recurse_dead(shooter IN number)
  2  as
  3  shot number;
  4  REMCNT number;
  5  PISTOL NUMBER;
  6  begin
  7  	DBMS_OUTPUT.ENABLE(100000);
  8  	SELECT count(*) INTO REMCNT from persons;
  9  	IF ( REMCNT > 1 )
 10  	THEN
 11  	   SELECT MAX(PERSON) INTO SHOT FROM PERSONS WHERE PERSON <> SHOOTER;
 12  	   DBMS_OUTPUT.PUT_LINE('SHOOTER - ' || SHOOTER || ' SHOT - ' || SHOT);
 13  	   DELETE FROM PERSONS WHERE PERSON = SHOT;
 14  	   COMMIT;
 15  	   SELECT count(*) INTO REMCNT from persons;
 16  	   IF ( REMCNT > 1 )
 17  	   THEN
 18  	      SELECT MAX(PERSON) INTO PISTOL  FROM PERSONS WHERE PERSON <> SHOOTER;
 19  	      RECURSE_DEAD(PISTOL);
 20  	   ELSE
 21  	      DBMS_OUTPUT.PUT_LINE('Last man standing is ' || SHOOTER);
 22  	   END IF;
 23  	ELSE
 24  	   DBMS_OUTPUT.PUT_LINE('Last man standing is ' || SHOOTER);
 25  	END IF;
 26  END RECURSE_DEAD;
 27  /

Procedure created.

SQL> exec recurse_dead(1);
SHOOTER - 1 SHOT - 6
SHOOTER - 5 SHOT - 4
SHOOTER - 3 SHOT - 5
SHOOTER - 2 SHOT - 3
SHOOTER - 1 SHOT - 2
Last man standing is 1

PL/SQL procedure successfully completed.

SQL> col res format a40 heading "Steps"
SQL> def N=5
SQL> with 
  2    humans as (
  3                select 1 num,  'Abel'      human from dual
  4      union all select 2 num,  'Bethany'   human from dual
  5      union all select 3 num,  'Cain'      human from dual
  6      union all select 4 num,  'Deborah'   human from dual
  7      union all select 5 num,  'Esther'    human from dual
  8      union all select 6 num,  'Felix'     human from dual
  9      union all select 7 num,  'Gideon'    human from dual
 10      union all select 8 num,  'Hillel'    human from dual
 11      union all select 9 num,  'Isaiah'    human from dual
 12      union all select 10 num, 'Jacob'     human from dual
 13      union all select 11 num, 'Kolariah'  human from dual
 14      union all select 12 num, 'Levi'      human from dual
 15      union all select 13 num, 'Michaiah'  human from dual
 16      union all select 14 num, 'Nathanael' human from dual
 17      union all select 15 num, 'Ozias'     human from dual
 18      union all select 16 num, 'Philemon'  human from dual
 19      union all select 17 num, 'Quincy'    human from dual
 20      union all select 18 num, 'Rebekah'   human from dual
 21      union all select 19 num, 'Sarah'     human from dual
 22      union all select 20 num, 'Thomas'    human from dual
 23      union all select 21 num, 'Uriah'     human from dual
 24      union all select 22 num, 'Vaniah'    human from dual
 25      union all select 23 num, 'Wendy'     human from dual
 26      union all select 24 num, 'Xena'      human from dual
 27      union all select 25 num, 'Yanael'    human from dual
 28      union all select 26 num, 'Zuriel'    human from dual
 29    )
 30  select decode(step,
 31                &N, 'Last Person Standing: '||killer,
 32                'Now '||killer||' kills '||dead) res
 33  -- , debug
 34  from ( select level rn, level step, 'N' killed from dual connect by level <= &N )
 35  model
 36    reference humans on ( select * from humans ) dimension by (num) measures (human)
 37    dimension by (rn)
 38    measures (step, killed,
 39              cast(null as varchar2(20)) killer, cast(null as varchar2(20)) dead,
 40              cast(null as number) ikiller, cast(null as number) idead,
 41              cast(null as number) prev_killer
 42  -- , cast(null as varchar2(50)) debug
 43             )
 44    rules upsert all sequential order iterate (&N) (
 45  -- debug[iteration_number+1]='kd='||wm_concat(killed)[rn between 1 and &N],
 46      -- Calculate new killer, first one (iteration 0) is number 1
 47      ikiller[iteration_number+1] = 
 48        decode(iteration_number, 
 49               0, 1,
 50               mod(max(decode(killed,'N',mod(step-nvl(prev_killer,0)+&N,&N)))[rn between 1 and &N]
 51                    + nvl(prev_killer[1],0),&N)
 52              ),
 53      -- Grab new killer name
 54      killer[iteration_number+1] = humans.human[ikiller[iteration_number+1]],
 55  -- debug[iteration_number+1]=debug[iteration_number+1]||' pk='||prev_killer[1]||' k='||ikiller[iteration_number+1]||'/'||killer[iteration_number+1],
 56      -- Set previous killer as new killer
 57      prev_killer[rn between 1 and &N] = ikiller[iteration_number+1],
 58  -- debug[iteration_number+1]=debug[iteration_number+1]||' pk2='||prev_killer[1],
 59      -- Calculate new killed (dead), first one (iteration 0) is last number
 60      idead[iteration_number+1] = 
 61        decode(iteration_number, 
 62               0, &N,
 63               mod(max(decode(killed,'N',mod(step-prev_killer+&N,&N)))[rn between 1 and &N]
 64                    + prev_killer[1], &N)
 65              ),
 66      -- Grab new dead human name
 67      dead[iteration_number+1] = humans.human[idead[iteration_number+1]],
 68  -- debug[iteration_number+1]=debug[iteration_number+1]||' d='||idead[iteration_number+1]||'/'||dead[iteration_number+1],
 69      -- Flag human as killed
 70      killed[idead[iteration_number+1]] = 'Y'
 71    )
 72  order by step
 73  /
Steps
----------------------------------------
Now Abel kills Esther
Now Deborah kills Cain
Now Bethany kills Abel
Now Deborah kills Bethany
Last Person Standing: Deborah

5 rows selected.

SQL> def N=6
SQL> /
Steps
----------------------------------------
Now Abel kills Felix
Now Esther kills Deborah
Now Cain kills Bethany
Now Abel kills Esther
Now Cain kills Abel
Last Person Standing: Cain

6 rows selected.