Companions of Travelers

Does anyone know about the the usefulness of the evolution for Companions of Travelers?
I got a few of them, I thought they were for level up and sort but they gave little exp so I sold them to save space... And I looked up about the evolution mode and their skills are like the Elves... Not really useful although their stats are pretty high, but is there any hidden combination?

Do you mean memory traveller?

They are for power releasing starter cards. Like molly, sean etc.

The bes and ladybugs you find are boosted so that they can be used as low rarity bruisers for getting achievements and levels that requires 4* or low team cost setups. There's also oddball SM battles where a few of these max level companions would come in handy. On your roster of teams, you should have a main, mono color, tumbler, and low teamcost utility deck. This fills in the last one nicely.

As feeders they're in between elves and witches as far as the experience yield goes. For example, putting a single 2* soulstone (9000 xp with same element bonus) into each gives:

3* elf: level 10, which in turn gives 16,050 xp when fed to another card of the same element
3* companion: level 10, gives 18,000 xp
3* witch: level 8, gives 19,800 xp

Then again, with the ease of obtaining great soulstones these days, I'm not sure how many people still level cards with feeders.

Hmm..... I Agree with Crazy achmed.
They are better as team for 4* achievement.. their hp is high for 4* card. Can be used to tank.
To level their skill up, may need 4* Elf.