4 Star undupped Tech to R5: Sentinel vs Ultron

Which undupped 4 star is worth R5
1) 4 Star Ultron Undupped to R5
2) 4 Star undupped Sentinal to R5
3) Wait for some other champion?

Comments

Sentinal

Spark and Star Lord are better than Ultron and Sentinel. Unless you have Spark and SL as 5*, I think you sould wait.