How do I make progress in Incursions?
I had just the right luck to start playing a week or two before that huge Deadpool event, and then getting a lot of more 6 stars from omega days event, so I ended up with more then 20 6 stars while still being at act 5. I ran out of ISO-8 because the Deadpool event got over, and so I ended up with about 5 rank 1 level 25 6*, 1 rank 2 level 35 6*, and 3 rank 3 level 45 6*. Rest of my 6 stars were rank 1 level 1.
This was where my problems began. In incursions, you are only allowed top zone bonuses from certain rooms, belonging to the tiers you have unlocked, and lucky for me, I reached tier 6, and could only get artifacts from the 4th sector and above. But, my top 3 champs only had about 12k hero rating each, and so I wasn't even able to go above zone 5 in sector 4.
Because of all these excess 6star champs, I can't make progress in incursions and am losing a lot of good rewards. Any tips to earn more incursion artifacts? ( my champs: spider ham, Emma frost, stark Spidey are top 3 champs, next is a maxed sig 0 not ascended human torch (9k hero rating), cap America IW 9k, awakened rank 2, and Spidey 2099 at 7.3k hero rating)