Character Leveling

Does anyone know how to level a character fast? I'm trying to level my new EV-2 and it is taking a really long time. If someone could help me. that would be great.

I think you can no longer speedfarm Harbinger, they patched it so you don't get xp after your first completion.

Just put the hero in your deck and win some matches i guess, the highest difficulty you can win. Only recently i also took a new hero to lvl 50. Wasn't paying attention, but he was lvl50 in less than 10 c1 matches for sure.

Note that all four heroes in your deck get the same amount of xp, so you don't need to actively play with the new one at all while leveling.