This card can only be Ritual Summoned with the Ritual Spell Card, "Ritual of Destruction". When this card is Ritual Summoned, destroy all other face-up monsters on the field with DEF less than or equal to this card's ATK. This card gains 100 ATK for each monster destroyed by this effect.
If the ATK of this monster is increased by ATK-boost trap or quick spell responding to the activation of this monster's effect, the effect destroys all other face-up monsters with DEF less than or equal to this card's ATK.
No: besides that Ritual of Destruction specifically states the level you must equal or surpass (7), there's also a ruling that makes this also count for cards such as Contract with the Abyss. In other words: you always look for the original printed level, not whatever level it currently is.
I have a king of games tier garlandolf deck that I may share later but one tip I'll give you is that if you're trying to run him in a deck you need 3 and 3 senju. you need to be able to sacrifice him to ritual summon himself and then play another card preferably senju or sonic bird same turn right after to get the 1 turn knockout.
hey I don´t know if you came back to read this but I managed to get to KoG with a last gamble garlandolf deck with this:
3 sphere kuriboh (if you only have one get another seer as well as a windstorm)
2 djinn (3*)
2 ritual of destruction
1 dark piercing light
2 magic drain (can be swapped out for windstorm, smoke grenade, a 2nd dark piercing light)
you can still make a decent ritual deck with only 2 senju's and a kuriboh but it will mainly involve cards like crystal seer, gale lizard or burbonic vermin to stall until you get the ritual spell cards, you can use 3 copies of storm to synergize with 'ritual of destruction' in case you have multiple copies, dark piercing light also important, = clear backrow and front row