SELECT ally_data.ally_name, characters.char_name as leader
FROM ally_data
LEFT JOIN characters ON characters.obj_Id = ally_data.leader_id
LIMIT(100);

SELECT clan_id FROM clan_data WHERE ally_id = $ally_id

SELECT COUNT(*) FROM characters WHERE clan_id IN ($clans_ids)

SELECT ally_data.ally_id, ally_data.ally_name, characters.char_name as leader,
(SELECT COUNT(0) FROM characters where characters.clanid IN (SELECT clan_data.clan_id FROM clan_data WHERE clan_data.ally_id = ally_data.ally_id)) as characters_count
FROM ally_data
LEFT JOIN characters ON characters.obj_Id = ally_data.leader_id
LIMIT 100;