Need help with 5.2.5 and 5.2.6

TheSquish671

I just finished 5.4.4 today and I'm going to run through ROL a few times to gather potions first, so I'll still have time to rank some champions before doing these quests. My questions are:
1)who should i bring in/rank up for my team?
2) which paths should i take for both quests?
3) who's best against the collector?

Here's my roster:



Thanks!