Onomat once got 2 XYZ on board cant do much either. one of their effect negates lvl 5 and above summoning. The other one negates monster effect activates on the field...But There is but... monster effect have 2 types, one activated in response certain condition. The other one activated without targeted effect. I gave good example. Tried already. Evilswarm halverk effect if attacked, target 1 monster opponent control return to hand, this one can be negated by XYZ Onomat. Kelbek effect any monster attack this card return to hand, this one cant be negated unless by counter trap Understand !!