i always wonder can a non-seasonal hero powerlvl a seasonal hero n vice versa?

actually i would like to plevel somebody else in return of a thank you for players that plevel me previously.
it's kind of return of debt, so that i feeling well by not owe any debt .
But my plevel-ed seasonal barbarian is lower level than my non-seasonal hero. Still not as efficiency as other non-seasonal hero in plevel. He cant even clear T6 alone ~.~
So wondering will that seasonal party with non-seasonal work.