How about a system where you can use Raid Energy to attack your own Titan Jr.
It can either work the same way the current Titan system works (your Titan Jr difficulty grows as you finish a Titan Jr) or the Titan Jr’s strength can be based on your level (realize the F2P will struggle here a bit).
The loot can be similar to say 3 x the loot of season 1 8x7, giving a reasonable level of loot to make it worthwhile. The current system of using a Raid Energy gives a few recruits which doesnt seem to have motivated anyone to use them for anything other than filling your chest when available.
The details can be flushed out but its the start of an idea.