Does anyone know how to increase you Might faster
Depends on your current situation. If your altar is full, invest 100 shard per duplicate to level their skill to 2/9. Each ordinary gain +19,5, elite +39 and legendary 58,5 might for one skill lvl. I do not recommend upgrading your elite heros, if you filled your altar with those right now, as you may consume them for other legendaries sooner or later (from rolling, special hero card, monthly druid etc).
And ofc, as mentioned above, level your duplicate heros. Each level for a legendary hero increases your might by 5 (ordinary by 2 and elite by 3.5).