Diemon Shark is such a powerful card at all levels of play. At lower levels it is just simply a sturdy tank that can take a few hits. Paired it with Frendul and it gives it more speed to its base of 4 which is already quite evasive for a tank. This card can single handedly take over a game and I have an example from one of my matches. It was an opportunity match and I had lost most of my team and at lvl 4 Diemon Shark blows through the enemy team because of its enrage ability at that level. His speed gets bumped up to 8 and causes a few misses and just tramples through the enemy lines.
https://splinterlands.com?p=battle&id=sl_e655e864e8a772a18687c615d664e608&ref=youngeagles95
To conclude this card in my opinion is vastly undervalued at the moment and I think it deserves more time in the spotlight. If you are in silver and are looking for a solid staple in the blue deck this is a cheap pickup for a great tank.