“Guardian Baou”, “Guardian Ceal”, “Guardian Elma”, “Guardian Grarl”, “Guardian Kay’est”, and “Guardian Tryce” all share some basic rules. Using “Guardian Elma” as an example:
You can Set “Guardian Elma” face-down without “Butterfly Dagger - Elma”, but you cannot Special Summon her face-down with “The Shallow Grave”, etc., unless you have “Butterfly Dagger - Elma” on your side of the field.
If your Set “Guardian Elma” is flipped face-up with “Swords of Revealing Light”, or by an attack, without “Butterfly Dagger - Elma” on your side of the field, she remains on the field because she was not Summoned.
“Guardian Elma” is a normally Summoned monster, not a Special Summon-only monster. So if Normal Summoned she counts as your 1 Summon for the turn.
You cannot use “Monster Reborn” on “Guardian Elma” if you do not have “Butterfly Dagger - Elma” on your side of the field.
If you activate “Monster Reborn” and target “Guardian Elma” while you have “Butterfly Dagger - Elma” on the field, and your opponent chains “Mystical Space Typhoon” to destroy “Butterfly Dagger - Elma”, so that it is no longer on the field when “Monster Reborn” resolves, you cannot Special Summon “Guardian Elma” and “Monster Reborn”’s effect disappears.
You can Normal Summon, Flip Summon, or Special Summon “Guardian Elma” even if your “Butterfly Dagger - Elma” has its effect negated by “Imperial Order”.
If “Cyber Jar” resolves and you pick up “Guardian Elma” without “Butterfly Dagger - Elma” on your side of the field, “Guardian Elma” is added to your hand.