The card you click combine on will be the one that has its stats changed – in other words, you don’t receive a brand new random card by combine two different ones, the first one you click combine on will be the one that you end up with.
1872 card which you can get from Captain America rifts. The two base stats are Attack Speed and Movement Speed, followed by four rather poor other stats which means it is a good candidate for upgrade.
By combining with the Battleworld card, you’ll see that the end result means four brand new stats including Physical Attack and Dodge – meaning that this was a fairly successful combine.
The other important factor to note is the Blue Gem number located by the side of the card towards the bottom. When you combine, this Gem number will not go any lower – only higher.
As a result of the combine, the original Gem 4 number became a Gem 5 based card meaning that the overall value of the two main base stats are slightly improved.