Within your alliance, it would be sweet if you could have the option to go into a titan battle WITH other alliance members and thus share skills across the team. If you start out lightly and just allow people to go in in pairs, one member clicks on the ‘FIGHT 2v1’ button and waits for however long it takes another member to click on it as well, then they go into battle together against the titan.
This would add another layer of complexity to alliance organisation because you can strategize which member should take in which hero. Some of the skills would need to be slightly toned down (like ‘all allies’ healers). We would need to see which member is waiting for a buddy so we can be sure of our set up.
With that, if you were able to show the other member’s heroes fighting alongside you (possibly in the background or off to the side in more of a 3D arrangement where they would be small and off in the distance because space on the screen is at a premium) that would be fun to watch. Especially if one day you can get 3 or 4 or even 5 members at once all hitting the titan together.