Tier List for new players
These champions can literally be used for any scenario asides from 5v5's. These champions have all been used for my ED10, SW10, arena and Ultimate Blitz. I still use these champions today over some Nat 5's that I've summoned and these were all obtained within a week of playing.
Rota - is probably the best starter farmer you can have. Even if faced with elemental disadvantage her kit provides great support for the rest of your team with increased atk spd, Cooldown reduction and can deal decent damage to clear trash mobs quickly. Can be obtained on common disks, rare discs and the nature bull raid.
Xenia - Is still one of the best healers in the game. Her kit provides CDR, Defense break, strips buffs and heals based on Max HP (great steel widow champ). She is probably one of the hardest to obtain of the three but can be easily obtained with a days worth of commitment farming light bull raids on Sundays. Make sure to save your gems to constantly refill your energy to farm.
Manas - provides CDR, provides additional healing, blocks buffs and applies OGD to shorten raid clear times. He's effective in clearing trash and provides a lot of dmg output for raid bosses from his OGD.
I know it may seem weird with just these two but as I said before my main focus is based on how easy these champions can be obtained and overall use. I prioritized these two because even with a full 5 star team. If you obtain all monsters from the tier one list and add one of these two, you can essentially 4 man anything with a high success rate. I selected shield users next on the tier list because as a new player you're going to need damage mitigation to survive the big hits raid bosses do. As you begin to 6 star then you can broaden your selection with champions.
Fire MG: Magical girls have actually been pretty common on the rare disk summoning table and feel within a few weeks of playing you'll probably end up with one soon. When paired with the 3 champions from tier 1, MG applies an additional OGD, additional support with strong heals/def buff and her ult helps absorb dmg and reflects an amount of damage that was absorbed back to the enemies.
Water Naga: although he's a nat 4, he can still be obtained easily through ritual summons and that is why I selected him. You might have a good chance at summoning him through rare discs but even if you have no luck there, the monsters required to ritual summon him are easily obtainable. Water naga provides a shield every 8 seconds without adept gear and when paired with the 3 tier 1 champions you can have 100 percent uptime with that shield.
I chose these 2 mainly because They're both needed for ritual summons and are the easiest to obtain.
Mojo is easily obtained as a two star monster from common disks. His kit is useful when progressing but isn't worth to 5 star some may disagree but I feel that overall his value decreases as you progress closer to end game content. Whats good about mojo is he applies decent buffs and debuffs to help you through the lower stages of raids and feel he does his work to help you get closer to end game at 4 stars maxed. Once you feel you're ready to move on to the later stages, he can then be used to ritual summon the water naga if you haven't summoned him already.
Water crowhag was my next choice because you have a good chance to summon her and if you have no luck she can also be obtained as a reward from the adventure board.
I like water crowhag because of the recent buff she received. If you decide to keep her and 6 star her, she is an op champion to use to speed up your SW/ED runs (she can also replace xenia as a stripper and I don't mean the exotic dancing kind of strip :D). A lot of people find her useful in arena offense as well. I know a few top arena players that use her in their teams. Also if you decide not to 6 star her she can be used as a ritual summon to help you get the water psion which can then be used to summon the water diva.
updated to include Dark Dryad - She is highly used for Arena Defense and is also a great addition to your raids and blitz teams. She can also be obtained from farking Dark Bull raids as well. She is also used to ritual summon water Diva.
This list is just my personal opinion on champions you should look for starting as a new player. I prioritize these champions based on how easy they can be obtained and overall usefulness. Having champions from tier 1 and tier 2 you already have a team that can clear blitz, raids up to level 10 and a decent farmer to help level up your champions.
Please refer to the builds and guides section of the website to see how to build each champion.