The Ancient Knights (also called Guardian Of The Hikari, ヒカリの守護者 in Super Sentai) is the ancestor of human and anime beings. Their leader is Lady Rekari (女王ムシマ, Joō Mushima), Kari's identity. There four knights are discovered by Samuel as Singular Rider to befriend the human and anime beings and Symbol Memories' creation was revealed.
Sir Tachiza (舘の王, Tachi no Ō knowns King of Tachi) is the one of the four ancient knights. He defeated the evil Memoripachi (死刑王, Shikei-ō), the "lost" Symbol Memory Leader. He used Longsword Memory to transform into Tachi Form.
Madame Foster (基山の婦人, Kiyama no Fujin knowns Lady of Kiyama) is the one of the four ancient knights. She defeated Dupinata (魔王歌姫, Maō Utahime), the Memoripachi's servant. She used Fujin Memory to transform into Fujin Form. Samuel revealed that Kiyama is her ancestor of Kiyama Hiroto.
Sir Gaia (電源の王, Dengen no Ō knowns King of Power)