The Reinforced trait allows a troop to regain 1 armor at the start of each turn, and Regeneration does the same but for life. Other similar traits could be added that allow troops to give 1 (life/armor) to an ally at the start of each turn, much like the legendary traits but less potent.
Another trait that would be interesting would be “create 1 (color) gem at the start of each turn” or "create 1 (color) gem when an (enemy/ally) casts a spell. Alternately, a trait could be “remove 1 (color) gem at the start of each turn”. Obviously, skulls would work too. These could theoretically cause a match, but I don’t think it would be the subject of any abuse since it would be out of the hands of the players.