Rank up Reinier now or wait?

https://preview.redd.it/xoly2jgadb3e1.png?width=1526&format=png&auto=webp&s=0fb79257c7314216fa1179f5b8c88aebc677836b

https://preview.redd.it/0fcyj65ddb3e1.png?width=1477&format=png&auto=webp&s=71bb99ae3bdc6ebd1b3b8ba16b79934e7f7b4614

Currently I have a 1/2 mythic reinier, and have enough to get him to mythic+. However, I haven't gotten a copy of Reinier yet from the all heroes available as of yet, and purchasing a dupe of him now would mean that later on, I'd have another reinier copy doing nothing for however long, probably forever. I can also start building Phraesto right now, however my next shot at getting reinier is in 17 days and can go up to 60+ more days if I want to get him through the guaranteed drop. What should I do here?