You can only use each of the (1)st and (2)nd effects of this card’s name once per turn.
(1) If you control 2 or more “Senka” monsters with different Attributes: You can declare 1 Attribute; the effects of all monsters your opponent controls of the declared Attribute cannot be activated until the end of this turn.
(2) If your opponent Special Summons a monster(s), OR if you activate a “Senka” monster’s effect: All “Senka” monsters you control gain 300 ATK for each “Senka” monster you control, until the end of this turn.