5☆ heroes are just so painfully rare to get. 
So targetting a specific portal in hopes of a specific hero often results in heartache 
That being said, I think the Covenant portal has even more brutal odds than most portals, and S5 might be more gentle. Either way - the chance is so low.
This thread here is such a great thing to swing by if one needs the odds visualized;Portal Summons Odds - Visualized
Covenant of Champions - as of Nov 2022
Season 5 - as of Oct 2022
Best of luck 
