What’s your main objective? If you want a good tank, the evidence from the SG statistical data published recently suggests he’s a good tank, and buffing his defensive stats will augment that.
If you want a good offensive hero, he’s a more questionable proposition. The 566 attack stat makes him less than inspiring in a purple stack, and even going full attack on the Druid build only nets 92 points, for a full scale attack stat if 658, which is a 4* caliber attack stat. Suffice it to say he’s not going to do crushing tile damage no matter what.
It’s possible to get him down to 12 tiles with a level 23 mana troop (the Druid bonus to mana is 5+20, so that’s not happening soon to help out), so you can mitigate the slowness.
My personal opinion is that having a killer raid defense tank is a status symbol, but not very valuable to game progress. It’s more useful if it’s an AW tank, but still not essential unless you’re facing very strong competition every war. I get by with an unemblemed Onatel war tank against top 50 competition. YMMV though.
If it were I, I’d have been giving the emblems to Mel to make him sturdier for offense and titans.