I have recently started using Onatel, i know she is a beast in offence. Can she be useful in war defence. I assume the AI does not know how to use her properly, thats why i am hesitant in putting her on the team.
Current lineup: Richard(costume), Tellu, Tibs (costume), Li xiu (costume), Kiril (costume). Mandatory purple tanks.
Should i replace Li xiu with Onatel or with any other member of the team? Where is Onatel the most useful in defence, tank, flang, wing?
Well if you’re running purple tanks, a popular strategy is to flank with yellow. So li xiu, tibs/rigard, onatel. I would use Rigard as the tank and get some emblems on him. Then I’d try to put some snipers at the wings. Not sure who else you have but telluria, rigard, and kiril is a lot of heal and little attack. Onatel can be mildly effective on defense but in my opinion I think she’s best at tank or right flank. I would check this resource and see who you have and where they are best positioned. 5* heroes positioning guide There’s also a list for four star heroes and I believe it will be in that post as well.
Thank you, i suspected as much that i should not use her in defence. And i have Richard on my team, not Rigard 
Haha! Not sure how I read that wrong. Apologies. But if you can get rigard, he’s an awesome purple tank if not one of the best. I didn’t mean you shouldn’t use onatel on defense. She’s good, don’t get me wrong. Personally though, I would give her a B+ just not an A. Other people may feel differently. Don’t just take my word for it. Let some other people give you their opinions. There’s way smarter people out there than me!
I have costumed rigard aswell, but always when i have faced him as a tank i have brought 3 yellows or a dispeller and negated the the heal/killed him fast, many people say that he is an amazing tank, so maybe i should reconsider.
I value damage more than healing, i used to have Chesthire cat instead of Kiril, maybe i should change back. We have an attack boost war coming up, so i thought Kiril could help stall the game a bit more, but probably im better off with the cat (dont have a super good sniper to put there)
I have many good heroes to add, but lack the mats right now to maximise them. I was thinking of:
li xiu, purple tank, onatel. Would i get super punished for having 2 yellows in my defence team? I would really like to hear opinions of people who have faced a strong emblemed Onatel in raids/war (in right wing position.)
War is much different from raids. Players only have a select number of each color they can use. So if your whole alliance is using purple, stacking with yellow is only effective for one or maybe two flags of six. So I would highly recommend costume rigard for your tank. And onatel flanking him is a very effective center. I have Onatel +17, and I’ve faced her a lot. She can be very punishing. And again this is just my opinion, but I run a 2111 on my war defense. I’ll leave you be now and let some better minds weigh in. Best of luck to you!