That doesn't sound hard. Yeah he can't use an artillery spell. But what about using a sword and making a sword wave. Same result different method. Just gotta be smart. Plus, heal and use body reinforcement at the same time means he should - theoretically - be faster and stronger than his peers.
Magic Enhancement says it can only be used to boost offensive magic, but is that right? What if he could use it to boost the 'strength' of something. Throw a reinforced, boosted, vibrating needle at an enemy and watch them die. Easy.
Plus, life magic. In other manga and anime this has something to do with health stealing or nature. Boost the growth of nature and become a Druid.