How can I find out how many 2* champions are there on Marvel Contest of the Champions?

Solution 1:

As of today there are 37 2* champions. There is no way to find out that information in game. The best source so far where people are trying to maintain a fairly updated list would be Wikia.

Marvel Contest of The Champions Wikia

They recently added a row with total number of champions. They do a very good job keeping it up to date.

There is also a very nice open project on github where you can see a map with all the champions and their synergies.

I have requested on Kabam forum to add a filter option to show all available champions.

Kabam forum proposal

Solution 2:

As of December 6, 2018, these are the champs by number:

2* 93

3* 123

4* 126

5* 92

6* 37

Reference http://marvel-contestofchampions.wikia.com/wiki/Tier