Let's talk about a card very annoying, but very helpful in many plays, including the use of malefics monsters: Skill Drain.
What else leaves doubt this card is that little part in parenthesis it says "its effects remain active." After all, she denies it and leaves to deny? I decided to pursue this remedy not only my doubts as well as all students.
I was in yugioh.wikia.com behind this card rulings, and found everything you were looking for and then some. I will be brief in explaining:
Denying continuous / non-chainable effects:
Effects like the Archlord Kristya, Blackwing - Vayu the Emblem of Honor, and monsters that fit this type of effect (effect of increased level, special summon, return to the deck and a few more) are denied. Some return to remove the Skill Drain Field as the effect of power suplier.
On Removing Lingering Effects Which Modify ATK / DEF
Effects such as Sea Dragon Lord Gishilnodon are denied enguanto Skill Drain is active, and after its destruction can be reactivated. Effects such as the Trident Dragon permace activated if Skill Drain is activated after the Summon it.
Effects such as the Light End Dragon, Dark End Dragon, Black winged Dragon and the like are denied to activate Skill Drain and do not return.
On Not Removing Previously-Resolved/Lingering Effects:
If Skill Drain is activated after activation effects like Cyber Dragon Zwei, Level Warrior, Scanner, Oracle of the Sun, BlackWing - Sirocco the Dawn and Splendid Rose, Skill Drain will not negate their effects.