Each time a Spell Card is activated, place 1 Spell Counter on this card when that Spell Card resolves. This card's Level is increased by the number of Spell Counters on this card. You can remove 3 Spell Counters from this card, then target 1 Quick-Play Spell Card in your Graveyard; Set that card to your Spell & Trap Zone. You can only use this effect of "Magical Something" once per turn.
Magical Citadel of Endymion works well with any cards that uses Spell Counters since it has multiple effects that circles around Spell Counter. First, it gains a Spell Counter when a Spell is activated. Next is the Spell Counter(s) of a destroyed card can be transferred to it. Its best effect is when you activate a card effect by removing a Spell Counter(s) from your side of the field, you can remove that many Spell Counters from this card instead. This card won't be easily destroyed too, since it can just remove a spell counter instead when it's about to get destroyed.
Spell Power Grasp instantly gives Magical Something 2 Spell Counters since its effect can give it 1 and Magical Something gains 1 Spell Counter when a Spell Card resolves. It's also better if you have Magical Citadel of Endymion in your field when you activate it since it also gains Spell Counters from Spell Cards.
These card is literally named Magical Something since it was released a year ago, although if translated from Japanese it means "Magical Absorber". Maybe there are just too many Magical archetypes that resulted Konami to say it to this card. Maybe later there will be a "Magical Whatever" card popping out.
This cards wording state that it gets a counter whenever a spell card is used and resolves... but this is only working for ones own spells atm, not opponents; other cards (citadel endymion) w/ same wording work when spells are played field wide
I'm curious how the level thing will be useful utility wise in the future. Only cards that matter currently would be ritual cards, aside from a few one off spell/trap cards that don't have much use in the current meta anyway