D.D. Scout Plane & D.D. Survivor Versus Royal Oppresion?

What happens? My Opponent can use it to negate but do they keep coming back until my opponent cant pay anymore or do they stay RFG when they are negated the first time. I need an Official ruling for regionals on Sunday.

it stays in rfg when they are negated the first time.

■If "D.D. Scout Plane" is removed from play, and during the End Phase its effect is activated and negated by "Royal Oppression", "D.D. Scout Plane" remains removed from play.[1]
http://yugioh.wikia.com/wiki/Card_Rulings:Royal_Oppression

D.D survivor won't come back because it specifies being face up. If the summon is negated, then survivor never hit the field, so it won't come back.

ok thanks guys, now what about skill drain? would they come back then since they activate in RFG?

Yes they would come back if skill drain is on the field. Their effects activate from RFG while Skill Drain on negates effects face up on the field.

thanks for all the help guys