Base 5* 4.80
Zimkitha, Zeline, Guinevere are a very good base for several of your blue & purple 5* heroes.
If you get blue 5* Ariel, she and green 5* Mother North will swap well with yellow 5* Guinevere depending on situation.
Guinevere 5* 4.80
Only Guardian Owl has a higher defense stat than Guinevere for 5* yellow. A Heal Over Time with enemy mana reduction and defense against its weak color. Very versatile and a 5* average mana speed healer.
Zimkitha & Zeline ( together they fight crime) 5* 4.80
All special skills help other heroes on same team, Zimkitha & Zeline are especially effective being fast mana speed - cleanse all allies, dispell all enemies, attack debuff all enemies and attack buff all allies.
Zeline has higher attack stat for more match/ board/ physical damage ( she is one of the most nerfed heroes in the game.)
Zimkitha has more HP for resisting DOTs longer.
The Double ZZs really compliment each other.
King Arthur 5* 4.80
Given your base, the only two blues better would be Ranger Athena followed by Ranger Alasie.
King Arthur -
enemy attack debuff,
enemy Elemental defense debuff,
good tanky anchor ( special skill defense buff - caster only but Huge buff ) to use Miracle / Revive scrolls if test team dead.
Since your attack team will usually have 1 healer, a tanky sniper with loads of special skill effects ( and Arthur has one of the best special skills- against titans, single Bosses and tanking ) will be a huge help. Bonus King Arthur is a PALADIN! Nice talent for a tanky sniper.
King Arthur has a much higher defense stat than Magi, combined with his special skill, he is much tankier than Magni. Both of their special skills are the same duration while Magni’s special does 0.5% more damage ( damage = attack stat x damage % plus magic ) than King Arthur.
Magni suffers from Original Hero Syndrome. King Arthur added after many new mechanics like Elemental defense debuff- which stacks with all/ rainbow defense debuff like Barbarian Grimm 4*+15’s Ramming Pulverizer or Ranger Tiburtus 4*+15 Improved Ramming Pulverizer ( see Notes).
Victor 5* 4.80
Victor -
very fast mana,
team defense buff ( +10% ally defense buff better than -10% enemy attack debuff since defense stat is non-linear ) this also over writes Challenging stage, Boss Ulmer’s defense debuff for two class quests,
stacking DOT,
Healing steal really helps with Field Aid (WR) and his high attack stat, lower defense stat.
Sartana suffers from Original Hero Syndrome and solo hero special skill. Victor added after Field Aid (WR) and very fast mana speed HotMs like Gravemaker. Victor helps the whole team with his defense buff.
Back ups / 5* 2.60 or 5* 3.70
Mother North 5* 3.70
Mother North at 5* 3.70 will help with many things including two class quests, does not need to be 5* 4.1 to be effective.
Guinevere is Heal Over Time which stacks with Mother North’s immediate heal AND Mother North’s minion HP Shields.
Guinevere more versatile - can be used for anything- but Mother North more useful for Class quests - luckily different classes- rare quests, seasonal events, challenge events and raid/ war attack teams. Eventually you will want both at 5* 4.80 but Guinevere first.
Mother North is not a good a solo healer as Ablerich - his Mana Over Time has been nerfed twice, but as a second healer Mother North is better with her higher chance to revive and minion HP shields for team mates at 100% HP.
Aegir 5* 2.60 or 5* 3.70
Aegis at 5* 2.60 or 5* 3.70 will help with many things.
If one of two nearby allies are ice- like Arthur - all 3 heroes share damage and any ice heroes then will have a non dispellable heal to help recover from shared damage and all 3 have a match/ board/ physical damage hp vamp to help recover from shared damage.
I am leveling mine from 5* 1.1 only because he saved my team in a class quest and I look forward to using him in the other. Aegir does not need to be 5* 4.1 to be effective.
Your a WIZARD Harry, er, Guinevere, Victor, Zeline
Yeah, 3 Wizards suck, but that is not the point of your first rainbow 5* 4.1 team.
Since you are spending 4* ascension items on a rainbow 5* 4.1 team you want the best team that works well together that you can swap in a few 4* 4.70 or 4*+15 or 4*+19 heroes depending on situation.
Rainbow teams with good synergy/ work well together are the single most efficient use of 3*/ 4* ascension items, Hero XP and refundable emblems.
Then you can start leveling 4* / 5* with more niche roles to swap in and out.
Once you have two good rainbow 5* 4.80 teams, then you can start leveling 5* heroes based on class. Until then a full class team of 4* heroes ( Barbarian through Wizard - ten 4* heroes total ) will be the best use of your emblems ( see notes ).