My one problem with lichens is this;
When they fuse, they are completely healed and all status effects are cured.

This makes no real logical sense.
So I suggest this simple tweak:

When Lichens fuse, the current health of both lichens is added together and all status effects are transferred to the newly created Lichen. The time limit on each status ailment will also be added up. All fused Lichens should have a small base amount of health so they cannot be killed too easily, the fused health of the smaller lichens would add into this.

The next idea would be bombs from the Blast Network being rewards for Krogmo tokens, going all the way up to 5 star. Each upgrade increases damage and the range of the bombs. These bombs will explode in the same pattern as in the arena and can either have an extremely fast charge time or instant charge. I for one favor instant charge, because even though they are spammable, a limit can be put on them and even if there is no limit it is hard to actually score a hit.
Of course, some tweaking could be involved.