Should I?

So basically I have 15 gems remaining, should I use them now while the Christmas Egg is on or accumulate more and wait for the next festival egg?? Will I have higher chances of getting a Legendary mon if I use the 15 gems one at a time while the special egg is on or not??

I’m sure there will be a festival soon with the new thunder first one so I think you should wait. You might get lucky and get him, first ones are usually really good.

I have 45 i am trying to get to 50 but not sure if i should wait either.

No, this festival has some spectacular legendaries, go for them. And the extra 10 in 1 offer is exclusive to the anniversary and Christmas festivals, so you won’t lose anything particular by not doing it on the later event.

Hard to say, they probably have New Year Egg like current one with increasing odds. I remember Anniversary Egg lasted 2 weeks, no reason they only do 1 week this time.

they extended the anniversary egg after they had some issues with it.

definitely save some and open 10 in 1 since you will get a free rare gem and higher chance of getting a legendary. btw christmas egg sucks wait for other festival egg