I am a strong supporter of leveling a rainbow 3* 3.50 team and a rainbow 4* 3.60 team before spending any 3* ascension items on getting a 4* 4.1 hero. Especially useful after you learn color stacking ( see Notes).
4* 3.60 are the most powerful heroes in the game with only farmable ascension materials .
Purple has some of the strongest 4* heroes in the game.
MY PERSONAL OPINION
I would level both Proteus and Sabina to 4* 3.60 using 1*/ 2* farmable ascension items. This costs the same Hero XP as leveling only one to 4* 4.70.
They are powerful at 4* 3.60 and let you see how they work with the rest of your hero roster.
I currently have Rigard 4* 4.70 ( my favorite 4* purple) second Rigard 4* 3.60 for War and color stacking ( I like the option on two healers per team especially on auto play. But don’t use same color healers on auto play ) might level a third Rigard 4* 3.60 for war if I ever summon one.
Working on two Sabina 4* 3.60 ( purple clone of Melendor but same color as Rigard so if Rigard has no mana, Sabina also has no mana, Melendor + Rigard better for auto play but Sabina + Melendor good against reflect all color damage Boss/ Titan buffs.), probably will stop at two Sabina 4* 3.60 to go with my Melendor 4* 4.70 and two Melendor 4* 3.60.
One Tiburtus 4* 3.60 for yellow bosses due to Ramming Pulverizer trio ( see Notes)
Edit:
I have played with Proteus on a very good friends account and he seems more versatile than Tiburtus, but trickier to use and not as useful against yellow titans as Ramming Pulverizer.
However you will eventually get Grimm from your legendary training and Grimm makes a decent stand in for Tiburtus on yellow titans. Proteus seems like he would be very good versus event Bosses and yellow rare Shiloh Desert Quest.
Take Proteus to 4* 3.60 and see what you think.
P.S. I love my Scarlett 4* 4.70 for use on my Wu Kong team and rare quests.
