Hey, Jashwita! To answer your question, no the dumping effect is not a hard once per turn. Crystal Rose's effect to send is a soft once per turn meaning that it can dump another card into the grave if Crystal Rose leaves the field and comes back or another copy is summoned. It's effect to banish a fusion to summon itself from grave IS a hard once per turn though, meaning it cannot happen more than once per turn as the card says "You can only use this effect of Crystal Rose once per turn". It is referring to the previous effect which is it's special summon from grave effect. The dumping effect as you can see has a period after the words "End Phase". Meaning that after the period there is another totally different effect. If both effects were a hard once per turn Crystal Rose would say at the very end of its text "You can only use each effect of Crystal Rose once per turn". Which it does not say, meaning the first effect is a soft once per turn and the second is a hard once per turn. Take Darklord Ixchel
as an example, at the end of its text it does say "You can only use each effect of Darklord Ixchel once per turn". Meaning both effects are indeed a hard once per turn. Hopefully this helps! If you have any other questions don't be afraid to reach out.