There are 2 ways: 1. obelisk summon with by tributing "Sanga of the Thunder", "Kazejin", and "Suijin"or 2. obelisk summon with by tributing "Gate Guardian" and 2x "Dynatherium" or "Dynatherium" and "Gravekeeper's Recruiter".
"Dynatherium" has this effect: "You can Special Summon this card (from your hand)." and, after that, summon Obelisk
Oh thanks. I guess I didn’t though about leaving the “guardians” on the field.
And dynatherium’s effect can’t be used twice in the same turn. That’s what made me confused. (Maybe use “the trick”?) So I guess you use that trap or the gravekeeper as a way of keeping them on the field.